Built 2026-10-14 (14 October 2026)

Waterloo Muni AP Weather Records (USW00094910)

Record envelope, standing records and threshold days for Waterloo Muni AP (USW00094910), Iowa, United States, with 77 years of record.

Key Facts for Waterloo Muni AP

  • Waterloo Muni AP (USW00094910) is a weather station in Iowa, United States at 42.55 latitude and -92.40 longitude, 264 m (867 ft) above sea level.
  • The station reports from 1950 to 2026, 77 years of record.
  • 1,464 records set at Waterloo Muni AP still stand.
  • Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Waterloo Muni AP set a daily record high maximum temperature of 30.6 C (87.1 F) on 10 October 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

  • Location: Iowa, United States, 42.55 latitude, -92.40 longitude.
  • Elevation: 264 m (867 ft).
  • Period of record: 1950 to 2026, 77 years.
  • Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

8 days at or beyond a record
Daily record high and record low at Waterloo Muni AP, with 2026 drawn through them The band shows the record high and record low for each calendar day at Waterloo Muni AP. The lines show the 2026 daily maximum and minimum. 8 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -40-200204060 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Waterloo Muni AP. The lines show the 2026 daily maximum and minimum. 8 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Waterloo Muni AP, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan18.3 C (64.9 F)-36.7 C (-34.1 F)9.4 C (48.9 F)-27.8 C (-18.0 F)
Feb25.6 C (78.1 F)-35.0 C (-31.0 F)18.9 C (66.0 F)-19.4 C (-2.9 F)
Mar30.6 C (87.1 F)-36.7 C (-34.1 F)30.6 C (87.1 F)-15.6 C (3.9 F)
Apr37.8 C (100.0 F)-20.0 C (-4.0 F)28.9 C (84.0 F)-5.0 C (23.0 F)
May36.1 C (97.0 F)-5.6 C (21.9 F)31.7 C (89.1 F)-2.2 C (28.0 F)
Jun39.4 C (102.9 F)3.3 C (37.9 F)33.3 C (91.9 F)7.8 C (46.0 F)
Jul40.6 C (105.1 F)5.6 C (42.1 F)35.6 C (96.1 F)13.3 C (55.9 F)
Aug40.6 C (105.1 F)0.6 C (33.1 F)32.2 C (90.0 F)10.0 C (50.0 F)
Sep37.8 C (100.0 F)-5.6 C (21.9 F)33.3 C (91.9 F)7.2 C (45.0 F)
Oct35.0 C (95.0 F)-11.7 C (10.9 F)30.6 C (87.1 F)4.4 C (39.9 F)
Nov26.7 C (80.1 F)-27.2 C (-17.0 F)n/an/a
Dec23.3 C (73.9 F)-33.9 C (-29.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Waterloo Muni AP by the year they were set 1,464 records at Waterloo Muni AP still stand. 1988 holds the most, with 39. 0102030401950: 201951: 271952: 151953: 181954: 131955: 241956: 111957: 71958: 81959: 211960: 231961: 111962: 211963: 301964: 261965: 311966: 251967: 331968: 141969: 241970: 261971: 231972: 201973: 141974: 211975: 311976: 221977: 301978: 91979: 141980: 111981: 141982: 171983: 331984: 191985: 271986: 221987: 171988: 391989: 241990: 141991: 251992: 161993: 131994: 191995: 101996: 191997: 131998: 221999: 172000: 272001: 142002: 182003: 162004: 202005: 152006: 202007: 132008: 92009: 92010: 72011: 102012: 382013: 92014: 212015: 132016: 72017: 182018: 202019: 172020: 182021: 262022: 102023: 282024: 252025: 202026: 131950195819661974198219901998200620142022
1,464 records at Waterloo Muni AP still stand. 1988 holds the most, with 39.
Standing records at Waterloo Muni AP by the year they were set
Year setStanding records
195020
195127
195215
195318
195413
195524
195611
19577
19588
195921
196023
196111
196221
196330
196426
196531
196625
196733
196814
196924
197026
197123
197220
197314
197421
197531
197622
197730
19789
197914
198011
198114
198217
198333
198419
198527
198622
198717
198839
198924
199014
199125
199216
199313
199419
199510
199619
199713
199822
199917
200027
200114
200218
200316
200420
200515
200620
200713
20089
20099
20107
201110
201238
20139
201421
201513
20167
201718
201820
201917
202018
202126
202210
202328
202425
202520
202613

All-Time Record Progression

6 new records
When Waterloo Muni AP set new all-time records 6 all-time records were set at Waterloo Muni AP between 16 January 1982 and 2 July 1999. Each dot is a new record. Record low maximum temperatureRecord high maximum temperatureRecord high minimum temperatureRecord daily precipitation16 January 1982: Record low maximum temperature -25.0 C (-13.0 F)24 December 1983: Record low maximum temperature -26.1 C (-15.0 F)31 July 1988: Record high maximum temperature 40.6 C (105.1 F)16 August 1988: Record high minimum temperature 26.7 C (80.1 F)2 February 1996: Record low maximum temperature -26.7 C (-16.1 F)2 July 1999: Record daily precipitation 139.4 mm (5.5 in)1985199019952000
6 all-time records were set at Waterloo Muni AP between 16 January 1982 and 2 July 1999. Each dot is a new record.
When Waterloo Muni AP set new all-time records
DateKindDetail
1982-01-16Record low maximum temperatureRecord low maximum temperature -25.0 C (-13.0 F)
1983-12-24Record low maximum temperatureRecord low maximum temperature -26.1 C (-15.0 F)
1988-07-31Record high maximum temperatureRecord high maximum temperature 40.6 C (105.1 F)
1988-08-16Record high minimum temperatureRecord high minimum temperature 26.7 C (80.1 F)
1996-02-02Record low maximum temperatureRecord low maximum temperature -26.7 C (-16.1 F)
1999-07-02Record daily precipitationRecord daily precipitation 139.4 mm (5.5 in)

Wettest Day of Each Month

Jul: 139.4 mm (5.5 in)
Record daily precipitation for each month at Waterloo Muni AP The wettest day on record for each calendar month at Waterloo Muni AP. The most was 139.4 mm (5.5 in) on 2 July 1999. 050100150 Jan: 51.1 mm (2.0 in), 22 January 2018 Jan Feb: 33.5 mm (1.3 in), 22 February 1981 Feb Mar: 49.5 mm (1.9 in), 30 March 1998 Mar Apr: 77.5 mm (3.1 in), 25 April 2008 Apr May: 86.6 mm (3.4 in), 29 May 1980 May Jun: 110.5 mm (4.4 in), 15 June 1980 Jun Jul: 139.4 mm (5.5 in), 2 July 1999 Jul Aug: 125.0 mm (4.9 in), 20 August 1966 Aug Sep: 82.0 mm (3.2 in), 1 September 2018 Sep Oct: 74.7 mm (2.9 in), 22 October 2020 Oct Nov: 61.0 mm (2.4 in), 4 November 1959 Nov Dec: 84.3 mm (3.3 in), 13 December 2015 Dec
The wettest day on record for each calendar month at Waterloo Muni AP. The most was 139.4 mm (5.5 in) on 2 July 1999.
Record daily precipitation for each month at Waterloo Muni AP
MonthRecord daily precipitation (mm)Date
Jan51.1 mm (2.0 in)22 January 2018
Feb33.5 mm (1.3 in)22 February 1981
Mar49.5 mm (1.9 in)30 March 1998
Apr77.5 mm (3.1 in)25 April 2008
May86.6 mm (3.4 in)29 May 1980
Jun110.5 mm (4.4 in)15 June 1980
Jul139.4 mm (5.5 in)2 July 1999
Aug125.0 mm (4.9 in)20 August 1966
Sep82.0 mm (3.2 in)1 September 2018
Oct74.7 mm (2.9 in)22 October 2020
Nov61.0 mm (2.4 in)4 November 1959
Dec84.3 mm (3.3 in)13 December 2015

Period of Record Coverage

1950 to 2026
Days with data per year at Waterloo Muni AP 77 years of record at Waterloo Muni AP, 1950 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1950, 2026. 1950: 275 of 365 days1951: 350 of 365 days1952: 364 of 366 days1953: 365 of 365 days1954: 362 of 365 days1955: 365 of 365 days1956: 366 of 366 days1957: 365 of 365 days1958: 365 of 365 days1959: 365 of 365 days1960: 366 of 366 days1961: 365 of 365 days1962: 365 of 365 days1963: 365 of 365 days1964: 366 of 366 days1965: 365 of 365 days1966: 365 of 365 days1967: 365 of 365 days1968: 366 of 366 days1969: 365 of 365 days1970: 365 of 365 days1971: 365 of 365 days1972: 366 of 366 days1973: 365 of 365 days1974: 365 of 365 days1975: 365 of 365 days1976: 366 of 366 days1977: 365 of 365 days1978: 365 of 365 days1979: 365 of 365 days1980: 366 of 366 days1981: 365 of 365 days1982: 365 of 365 days1983: 365 of 365 days1984: 366 of 366 days1985: 365 of 365 days1986: 365 of 365 days1987: 365 of 365 days1988: 366 of 366 days1989: 365 of 365 days1990: 365 of 365 days1991: 365 of 365 days1992: 366 of 366 days1993: 365 of 365 days1994: 365 of 365 days1995: 365 of 365 days1996: 366 of 366 days1997: 365 of 365 days1998: 365 of 365 days1999: 365 of 365 days2000: 366 of 366 days2001: 365 of 365 days2002: 365 of 365 days2003: 365 of 365 days2004: 366 of 366 days2005: 365 of 365 days2006: 365 of 365 days2007: 365 of 365 days2008: 366 of 366 days2009: 365 of 365 days2010: 365 of 365 days2011: 365 of 365 days2012: 366 of 366 days2013: 365 of 365 days2014: 365 of 365 days2015: 365 of 365 days2016: 366 of 366 days2017: 365 of 365 days2018: 365 of 365 days2019: 365 of 365 days2020: 366 of 366 days2021: 365 of 365 days2022: 365 of 365 days2023: 365 of 365 days2024: 366 of 366 days2025: 365 of 365 days2026: 283 of 365 days19501960197019801990200020102020
77 years of record at Waterloo Muni AP, 1950 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1950, 2026.
Days with data per year at Waterloo Muni AP
YearDays with dataShare of yearComplete
195027575%No
195135096%Yes
195236499%Yes
1953365100%Yes
195436299%Yes
1955365100%Yes
1956366100%Yes
1957365100%Yes
1958365100%Yes
1959365100%Yes
1960366100%Yes
1961365100%Yes
1962365100%Yes
1963365100%Yes
1964366100%Yes
1965365100%Yes
1966365100%Yes
1967365100%Yes
1968366100%Yes
1969365100%Yes
1970365100%Yes
1971365100%Yes
1972366100%Yes
1973365100%Yes
1974365100%Yes
1975365100%Yes
1976366100%Yes
1977365100%Yes
1978365100%Yes
1979365100%Yes
1980366100%Yes
1981365100%Yes
1982365100%Yes
1983365100%Yes
1984366100%Yes
1985365100%Yes
1986365100%Yes
1987365100%Yes
1988366100%Yes
1989365100%Yes
1990365100%Yes
1991365100%Yes
1992366100%Yes
1993365100%Yes
1994365100%Yes
1995365100%Yes
1996366100%Yes
1997365100%Yes
1998365100%Yes
1999365100%Yes
2000366100%Yes
2001365100%Yes
2002365100%Yes
2003365100%Yes
2004366100%Yes
2005365100%Yes
2006365100%Yes
2007365100%Yes
2008366100%Yes
2009365100%Yes
2010365100%Yes
2011365100%Yes
2012366100%Yes
2013365100%Yes
2014365100%Yes
2015365100%Yes
2016366100%Yes
2017365100%Yes
2018365100%Yes
2019365100%Yes
2020366100%Yes
2021365100%Yes
2022365100%Yes
2023365100%Yes
2024366100%Yes
2025365100%Yes
202628378%No

Latest Records

20
Latest records at Waterloo Muni AP
DateStationRecordValueBeat old record byOld record stoodSignificance
10 October 2026Waterloo Muni AP, USdaily high max (Provisional)30.6 C (87.1 F)1.2 C (2.2 F)64 years27 of 100 (Routine)
1 October 2026Waterloo Muni AP, USdaily rain (Provisional)73.9 mm (2.9 in)22.3 mm (0.9 in)8 years29 of 100 (Routine)
3 September 2026Waterloo Muni AP, USdaily high min (Provisional)22.2 C (72.0 F)1.1 C (2.0 F)65 years28 of 100 (Routine)
20 July 2026Waterloo Muni AP, USdaily rain50.5 mm (2.0 in)1.5 mm (0.06 in)27 years15 of 100 (Routine)
1 July 2026Waterloo Muni AP, USdaily high min25.0 C (77.0 F)1.1 C (2.0 F)56 years26 of 100 (Routine)
30 June 2026Waterloo Muni AP, USmonthly high min25.6 C (78.1 F)0.6 C (1.1 F)72 years39 of 100 (Notable)
29 June 2026Waterloo Muni AP, USmonthly high min (Tie)25.0 C (77.0 F)tie72 years9 of 100 (Routine)
11 June 2026Waterloo Muni AP, USdaily rain49.8 mm (2.0 in)7.4 mm (0.29 in)28 years20 of 100 (Routine)
14 April 2026Waterloo Muni AP, USdaily high min13.9 C (57.0 F)0.6 C (1.1 F)49 years22 of 100 (Routine)
3 April 2026Waterloo Muni AP, USdaily rain33.5 mm (1.3 in)9.1 mm (0.36 in)8 years17 of 100 (Routine)
30 March 2026Waterloo Muni AP, USdaily high max30.0 C (86.0 F)1.1 C (2.0 F)59 years25 of 100 (Routine)
21 March 2026Waterloo Muni AP, USmonthly high max (Tie)30.6 C (87.1 F)tie39 years7 of 100 (Routine)
16 March 2026Waterloo Muni AP, USdaily low max-6.7 C (19.9 F)4.0 C (7.2 F)12 years15 of 100 (Routine)
9 March 2026Waterloo Muni AP, USdaily high max (Tie)20.6 C (69.1 F)tie4 years2 of 100 (Routine)
9 March 2026Waterloo Muni AP, USdaily high min (Tie)5.6 C (42.1 F)tie4 years2 of 100 (Routine)
6 March 2026Waterloo Muni AP, USdaily rain40.9 mm (1.6 in)17.0 mm (0.7 in)43 years42 of 100 (Notable)
6 March 2026Waterloo Muni AP, USdaily high min7.2 C (45.0 F)0.5 C (0.9 F)43 years19 of 100 (Routine)
19 February 2026Waterloo Muni AP, USdaily snowfall11.7 cm (4.6 in)5.3 cm (2.1 in)16 years24 of 100 (Routine)
16 February 2026Waterloo Muni AP, USdaily high max18.9 C (66.0 F)2.2 C (4.0 F)44 years23 of 100 (Routine)
16 February 2026Waterloo Muni AP, USdaily high min3.3 C (37.9 F)0.5 C (0.9 F)42 years19 of 100 (Routine)

Climate Trend

75 complete years, 1951 to 2025
Annual mean temperature at Waterloo Muni AP as warming stripes, 1951 to 2025 One stripe for each of 75 complete years at Waterloo Muni AP, 1951 to 2025. Blue stripes are years cooler than the station's own mean of 8.5 C (47.3 F); red stripes are warmer. The coolest year was 1972, at 6.5 C (43.6 F), and the warmest was 2024, at 11.3 C (52.4 F). The strongest colour marks a difference of 2.9 C (5.2 F). 1951: 7.0 C, -1.5 C from the station mean1952: 9.3 C, +0.8 C from the station mean1953: 9.7 C, +1.3 C from the station mean1954: 9.7 C, +1.3 C from the station mean1955: 8.8 C, +0.3 C from the station mean1956: 8.4 C, -0.1 C from the station mean1957: 8.4 C, -0.1 C from the station mean1958: 7.9 C, -0.6 C from the station mean1959: 8.2 C, -0.3 C from the station mean1960: 7.6 C, -0.8 C from the station mean1961: 8.1 C, -0.4 C from the station mean1962: 7.6 C, -0.9 C from the station mean1963: 8.2 C, -0.3 C from the station mean1964: 8.5 C, 0.0 C from the station mean1965: 7.3 C, -1.1 C from the station mean1966: 7.7 C, -0.8 C from the station mean1967: 7.1 C, -1.3 C from the station mean1968: 7.9 C, -0.6 C from the station mean1969: 6.8 C, -1.7 C from the station mean1970: 7.2 C, -1.3 C from the station mean1971: 7.0 C, -1.5 C from the station mean1972: 6.5 C, -2.0 C from the station mean1973: 9.0 C, +0.6 C from the station mean1974: 8.0 C, -0.5 C from the station mean1975: 8.1 C, -0.3 C from the station mean1976: 7.5 C, -1.0 C from the station mean1977: 7.5 C, -0.9 C from the station mean1978: 6.7 C, -1.8 C from the station mean1979: 7.3 C, -1.2 C from the station mean1980: 8.2 C, -0.3 C from the station mean1981: 8.6 C, +0.1 C from the station mean1982: 7.6 C, -0.9 C from the station mean1983: 8.5 C, 0.0 C from the station mean1984: 8.3 C, -0.2 C from the station mean1985: 7.4 C, -1.1 C from the station mean1986: 8.4 C, -0.1 C from the station mean1987: 10.2 C, +1.8 C from the station mean1988: 8.8 C, +0.3 C from the station mean1989: 7.7 C, -0.8 C from the station mean1990: 9.3 C, +0.8 C from the station mean1991: 8.8 C, +0.3 C from the station mean1992: 8.6 C, +0.1 C from the station mean1993: 8.0 C, -0.5 C from the station mean1994: 8.4 C, -0.1 C from the station mean1995: 8.5 C, +0.1 C from the station mean1996: 7.2 C, -1.3 C from the station mean1997: 7.9 C, -0.5 C from the station mean1998: 10.3 C, +1.8 C from the station mean1999: 9.6 C, +1.2 C from the station mean2000: 8.9 C, +0.4 C from the station mean2001: 9.1 C, +0.6 C from the station mean2002: 9.6 C, +1.1 C from the station mean2003: 8.8 C, +0.4 C from the station mean2004: 8.9 C, +0.4 C from the station mean2005: 9.0 C, +0.6 C from the station mean2006: 9.6 C, +1.1 C from the station mean2007: 8.8 C, +0.3 C from the station mean2008: 7.3 C, -1.2 C from the station mean2009: 7.8 C, -0.7 C from the station mean2010: 8.6 C, +0.1 C from the station mean2011: 8.8 C, +0.4 C from the station mean2012: 10.8 C, +2.3 C from the station mean2013: 7.6 C, -0.8 C from the station mean2014: 6.9 C, -1.6 C from the station mean2015: 9.2 C, +0.7 C from the station mean2016: 10.0 C, +1.5 C from the station mean2017: 9.5 C, +1.0 C from the station mean2018: 8.1 C, -0.3 C from the station mean2019: 8.5 C, 0.0 C from the station mean2020: 9.8 C, +1.4 C from the station mean2021: 10.1 C, +1.7 C from the station mean2022: 8.7 C, +0.2 C from the station mean2023: 10.9 C, +2.4 C from the station mean2024: 11.3 C, +2.9 C from the station mean2025: 9.9 C, +1.4 C from the station mean19511960197019801990200020102020
One stripe for each of 75 complete years at Waterloo Muni AP, 1951 to 2025. Blue stripes are years cooler than the station's own mean of 8.5 C (47.3 F); red stripes are warmer. The coolest year was 1972, at 6.5 C (43.6 F), and the warmest was 2024, at 11.3 C (52.4 F). The strongest colour marks a difference of 2.9 C (5.2 F).
Annual mean temperature at Waterloo Muni AP as warming stripes, 1951 to 2025
YearAnnual mean temperatureDifference from the station mean
19517.0 C-1.49 C
19529.3 C+0.79 C
19539.7 C+1.27 C
19549.7 C+1.27 C
19558.8 C+0.30 C
19568.4 C-0.08 C
19578.4 C-0.09 C
19587.9 C-0.62 C
19598.2 C-0.26 C
19607.6 C-0.84 C
19618.1 C-0.36 C
19627.6 C-0.90 C
19638.2 C-0.31 C
19648.5 C-0.02 C
19657.3 C-1.14 C
19667.7 C-0.78 C
19677.1 C-1.34 C
19687.9 C-0.62 C
19696.8 C-1.65 C
19707.2 C-1.30 C
19717.0 C-1.49 C
19726.5 C-2.02 C
19739.0 C+0.57 C
19748.0 C-0.46 C
19758.1 C-0.33 C
19767.5 C-1.01 C
19777.5 C-0.93 C
19786.7 C-1.75 C
19797.3 C-1.15 C
19808.2 C-0.25 C
19818.6 C+0.11 C
19827.6 C-0.90 C
19838.5 C+0.03 C
19848.3 C-0.16 C
19857.4 C-1.07 C
19868.4 C-0.06 C
198710.2 C+1.76 C
19888.8 C+0.28 C
19897.7 C-0.80 C
19909.3 C+0.81 C
19918.8 C+0.30 C
19928.6 C+0.14 C
19938.0 C-0.45 C
19948.4 C-0.06 C
19958.5 C+0.06 C
19967.2 C-1.27 C
19977.9 C-0.53 C
199810.3 C+1.78 C
19999.6 C+1.16 C
20008.9 C+0.42 C
20019.1 C+0.59 C
20029.6 C+1.10 C
20038.8 C+0.36 C
20048.9 C+0.42 C
20059.0 C+0.57 C
20069.6 C+1.13 C
20078.8 C+0.32 C
20087.3 C-1.20 C
20097.8 C-0.67 C
20108.6 C+0.13 C
20118.8 C+0.36 C
201210.8 C+2.29 C
20137.6 C-0.83 C
20146.9 C-1.62 C
20159.2 C+0.74 C
201610.0 C+1.52 C
20179.5 C+0.99 C
20188.1 C-0.34 C
20198.5 C+0.01 C
20209.8 C+1.36 C
202110.1 C+1.66 C
20228.7 C+0.21 C
202310.9 C+2.39 C
202411.3 C+2.86 C
20259.9 C+1.42 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1951 to 2025. In Fahrenheit: 0.4 F (0.2 to 0.6) per decade. The slope is a straight line fitted to 75 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Waterloo Muni AP
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.2 C (0.1 to 0.3) per decade0.4 F (0.2 to 0.6) per decade1951 to 202575Rise
Mean daily maximum0.2 C (0.1 to 0.4) per decade0.4 F (0.2 to 0.6) per decade1951 to 202575Rise
Mean daily minimum0.2 C (0.1 to 0.3) per decade0.4 F (0.2 to 0.5) per decade1951 to 202575Rise

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1950 to 2026
Yearly extremes at Waterloo Muni AP: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)40.6 C (105.1 F)198835.6 C (96.1 F)77
Coldest night (TNn)-36.7 C (-34.1 F)1962-28.9 C (-20.0 F)77
Wettest day (Rx1day)139.4 mm (5.5 in)199959.7 mm (2.4 in)77
Wettest five days (Rx5day)238.0 mm (9.4 in)196894.8 mm (3.7 in)77
Longest dry spell (CDD)45 days199923 days77

Hottest day (TXx)

Hottest day (TXx) at Waterloo Muni AP by year The hottest day of the year at Waterloo Muni AP, 1950 to 2026. The record is 40.6 C (105.1 F) in 1988, marked on the chart; the median year is 35.6 C (96.1 F). 3234363840421960198020002020Record: 40.6 C (105.1 F) in 1988
The hottest day of the year at Waterloo Muni AP, 1950 to 2026. The record is 40.6 C (105.1 F) in 1988, marked on the chart; the median year is 35.6 C (96.1 F).
Hottest day (TXx) at Waterloo Muni AP by year
YearHottest day (TXx)
195033.9 C (93.0 F)
195133.3 C (91.9 F)
195236.1 C (97.0 F)
195336.7 C (98.1 F)
195437.2 C (99.0 F)
195539.4 C (102.9 F)
195636.7 C (98.1 F)
195738.3 C (100.9 F)
195833.9 C (93.0 F)
195934.4 C (93.9 F)
196034.4 C (93.9 F)
196134.4 C (93.9 F)
196232.8 C (91.0 F)
196336.7 C (98.1 F)
196436.1 C (97.0 F)
196535.0 C (95.0 F)
196637.2 C (99.0 F)
196734.4 C (93.9 F)
196833.9 C (93.0 F)
196933.3 C (91.9 F)
197037.2 C (99.0 F)
197133.9 C (93.0 F)
197234.4 C (93.9 F)
197334.4 C (93.9 F)
197436.1 C (97.0 F)
197534.4 C (93.9 F)
197637.2 C (99.0 F)
197737.8 C (100.0 F)
197835.0 C (95.0 F)
197932.8 C (91.0 F)
198037.8 C (100.0 F)
198134.4 C (93.9 F)
198236.1 C (97.0 F)
198337.8 C (100.0 F)
198436.7 C (98.1 F)
198538.9 C (102.0 F)
198635.0 C (95.0 F)
198737.8 C (100.0 F)
198840.6 C (105.1 F)
198938.3 C (100.9 F)
199036.7 C (98.1 F)
199136.7 C (98.1 F)
199233.3 C (91.9 F)
199333.3 C (91.9 F)
199434.4 C (93.9 F)
199537.8 C (100.0 F)
199637.2 C (99.0 F)
199735.6 C (96.1 F)
199836.7 C (98.1 F)
199935.0 C (95.0 F)
200037.2 C (99.0 F)
200135.6 C (96.1 F)
200235.6 C (96.1 F)
200336.7 C (98.1 F)
200432.8 C (91.0 F)
200534.4 C (93.9 F)
200635.6 C (96.1 F)
200735.0 C (95.0 F)
200833.9 C (93.0 F)
200933.9 C (93.0 F)
201033.9 C (93.0 F)
201137.2 C (99.0 F)
201240.0 C (104.0 F)
201337.2 C (99.0 F)
201433.9 C (93.0 F)
201535.0 C (95.0 F)
201635.0 C (95.0 F)
201735.0 C (95.0 F)
201836.1 C (97.0 F)
201935.0 C (95.0 F)
202035.6 C (96.1 F)
202137.8 C (100.0 F)
202236.1 C (97.0 F)
202340.6 C (105.1 F)
202436.7 C (98.1 F)
202535.6 C (96.1 F)
202635.6 C (96.1 F)

Coldest night (TNn)

Coldest night (TNn) at Waterloo Muni AP by year The coldest night of the year at Waterloo Muni AP, 1950 to 2026. The record is -36.7 C (-34.1 F) in 1962, marked on the chart; the median year is -28.9 C (-20.0 F). -40-35-30-25-201960198020002020Record: -36.7 C (-34.1 F) in 1962
The coldest night of the year at Waterloo Muni AP, 1950 to 2026. The record is -36.7 C (-34.1 F) in 1962, marked on the chart; the median year is -28.9 C (-20.0 F).
Coldest night (TNn) at Waterloo Muni AP by year
YearColdest night (TNn)
1950-32.2 C (-26.0 F)
1951-32.8 C (-27.0 F)
1952-25.0 C (-13.0 F)
1953-24.4 C (-11.9 F)
1954-26.7 C (-16.1 F)
1955-27.2 C (-17.0 F)
1956-29.4 C (-20.9 F)
1957-28.3 C (-18.9 F)
1958-28.9 C (-20.0 F)
1959-27.2 C (-17.0 F)
1960-28.9 C (-20.0 F)
1961-32.2 C (-26.0 F)
1962-36.7 C (-34.1 F)
1963-33.3 C (-27.9 F)
1964-23.9 C (-11.0 F)
1965-28.9 C (-20.0 F)
1966-32.2 C (-26.0 F)
1967-32.2 C (-26.0 F)
1968-28.9 C (-20.0 F)
1969-26.1 C (-15.0 F)
1970-35.0 C (-31.0 F)
1971-32.8 C (-27.0 F)
1972-32.2 C (-26.0 F)
1973-27.2 C (-17.0 F)
1974-32.2 C (-26.0 F)
1975-27.8 C (-18.0 F)
1976-30.6 C (-23.1 F)
1977-33.3 C (-27.9 F)
1978-28.3 C (-18.9 F)
1979-31.1 C (-24.0 F)
1980-25.6 C (-14.1 F)
1981-27.2 C (-17.0 F)
1982-32.8 C (-27.0 F)
1983-32.2 C (-26.0 F)
1984-27.2 C (-17.0 F)
1985-31.7 C (-25.1 F)
1986-30.0 C (-22.0 F)
1987-23.3 C (-9.9 F)
1988-29.4 C (-20.9 F)
1989-31.7 C (-25.1 F)
1990-26.7 C (-16.1 F)
1991-28.9 C (-20.0 F)
1992-22.2 C (-8.0 F)
1993-27.2 C (-17.0 F)
1994-36.1 C (-33.0 F)
1995-22.8 C (-9.0 F)
1996-35.0 C (-31.0 F)
1997-27.2 C (-17.0 F)
1998-23.9 C (-11.0 F)
1999-30.0 C (-22.0 F)
2000-33.9 C (-29.0 F)
2001-24.4 C (-11.9 F)
2002-20.6 C (-5.1 F)
2003-25.0 C (-13.0 F)
2004-26.1 C (-15.0 F)
2005-28.9 C (-20.0 F)
2006-28.3 C (-18.9 F)
2007-27.2 C (-17.0 F)
2008-33.9 C (-29.0 F)
2009-36.7 C (-34.1 F)
2010-28.9 C (-20.0 F)
2011-29.4 C (-20.9 F)
2012-27.2 C (-17.0 F)
2013-29.3 C (-20.7 F)
2014-31.6 C (-24.9 F)
2015-31.0 C (-23.8 F)
2016-27.1 C (-16.8 F)
2017-27.1 C (-16.8 F)
2018-29.3 C (-20.7 F)
2019-34.9 C (-30.8 F)
2020-25.5 C (-13.9 F)
2021-29.3 C (-20.7 F)
2022-27.7 C (-17.9 F)
2023-29.3 C (-20.7 F)
2024-26.0 C (-14.8 F)
2025-27.1 C (-16.8 F)
2026-27.8 C (-18.0 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Waterloo Muni AP by year The wettest day of the year at Waterloo Muni AP, 1950 to 2026. The record is 139.4 mm (5.5 in) in 1999, marked on the chart; the median year is 59.7 mm (2.4 in). 0501001501960198020002020Record: 139.4 mm (5.5 in) in 1999
The wettest day of the year at Waterloo Muni AP, 1950 to 2026. The record is 139.4 mm (5.5 in) in 1999, marked on the chart; the median year is 59.7 mm (2.4 in).
Wettest day (Rx1day) at Waterloo Muni AP by year
YearWettest day (Rx1day)
195078.2 mm (3.1 in)
195172.6 mm (2.9 in)
195238.1 mm (1.5 in)
195336.1 mm (1.4 in)
195467.3 mm (2.6 in)
195544.2 mm (1.7 in)
195662.2 mm (2.4 in)
195750.3 mm (2.0 in)
195864.0 mm (2.5 in)
195961.0 mm (2.4 in)
196053.6 mm (2.1 in)
196175.4 mm (3.0 in)
196254.4 mm (2.1 in)
196372.9 mm (2.9 in)
196471.1 mm (2.8 in)
196559.7 mm (2.4 in)
1966125.0 mm (4.9 in)
196753.8 mm (2.1 in)
1968134.9 mm (5.3 in)
196956.1 mm (2.2 in)
197041.9 mm (1.6 in)
197141.7 mm (1.6 in)
197258.4 mm (2.3 in)
197369.9 mm (2.8 in)
197459.4 mm (2.3 in)
197535.6 mm (1.4 in)
197653.8 mm (2.1 in)
197754.1 mm (2.1 in)
197877.5 mm (3.1 in)
197967.3 mm (2.6 in)
1980110.5 mm (4.4 in)
198133.5 mm (1.3 in)
198249.3 mm (1.9 in)
198350.8 mm (2.0 in)
198446.5 mm (1.8 in)
198541.9 mm (1.6 in)
198670.9 mm (2.8 in)
198755.9 mm (2.2 in)
198846.2 mm (1.8 in)
198936.8 mm (1.4 in)
199058.7 mm (2.3 in)
199191.9 mm (3.6 in)
199252.8 mm (2.1 in)
199379.5 mm (3.1 in)
199474.7 mm (2.9 in)
199534.3 mm (1.4 in)
199655.1 mm (2.2 in)
199759.4 mm (2.3 in)
199884.6 mm (3.3 in)
1999139.4 mm (5.5 in)
200065.5 mm (2.6 in)
200156.3 mm (2.2 in)
200251.5 mm (2.0 in)
200360.1 mm (2.4 in)
200448.5 mm (1.9 in)
200581.8 mm (3.2 in)
200659.7 mm (2.4 in)
200769.9 mm (2.8 in)
200877.5 mm (3.1 in)
200975.4 mm (3.0 in)
201066.8 mm (2.6 in)
201143.9 mm (1.7 in)
201254.1 mm (2.1 in)
201378.5 mm (3.1 in)
201452.6 mm (2.1 in)
2015104.1 mm (4.1 in)
201681.5 mm (3.2 in)
201742.4 mm (1.7 in)
201882.0 mm (3.2 in)
201951.8 mm (2.0 in)
202074.7 mm (2.9 in)
202145.7 mm (1.8 in)
202262.2 mm (2.4 in)
202338.6 mm (1.5 in)
202470.9 mm (2.8 in)
202564.0 mm (2.5 in)
202673.9 mm (2.9 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Waterloo Muni AP by year The wettest five days of the year at Waterloo Muni AP, 1950 to 2026. The record is 238.0 mm (9.4 in) in 1968, marked on the chart; the median year is 94.8 mm (3.7 in). 0501001502002501960198020002020Record: 238.0 mm (9.4 in) in 1968
The wettest five days of the year at Waterloo Muni AP, 1950 to 2026. The record is 238.0 mm (9.4 in) in 1968, marked on the chart; the median year is 94.8 mm (3.7 in).
Wettest five days (Rx5day) at Waterloo Muni AP by year
YearWettest five days (Rx5day)
195087.1 mm (3.4 in)
1951102.0 mm (4.0 in)
195270.9 mm (2.8 in)
195355.1 mm (2.2 in)
195493.5 mm (3.7 in)
195584.6 mm (3.3 in)
195669.4 mm (2.7 in)
195768.7 mm (2.7 in)
195864.8 mm (2.6 in)
1959135.2 mm (5.3 in)
1960106.0 mm (4.2 in)
1961118.7 mm (4.7 in)
196270.9 mm (2.8 in)
1963157.7 mm (6.2 in)
196483.6 mm (3.3 in)
1965114.0 mm (4.5 in)
1966134.1 mm (5.3 in)
196778.1 mm (3.1 in)
1968238.0 mm (9.4 in)
1969126.7 mm (5.0 in)
197089.4 mm (3.5 in)
197167.6 mm (2.7 in)
197275.6 mm (3.0 in)
197390.5 mm (3.6 in)
197470.4 mm (2.8 in)
197543.6 mm (1.7 in)
197687.6 mm (3.4 in)
197773.1 mm (2.9 in)
1978139.4 mm (5.5 in)
197984.6 mm (3.3 in)
1980130.8 mm (5.1 in)
198170.8 mm (2.8 in)
198265.6 mm (2.6 in)
1983102.2 mm (4.0 in)
198487.8 mm (3.5 in)
198562.5 mm (2.5 in)
198681.3 mm (3.2 in)
198795.2 mm (3.7 in)
198849.2 mm (1.9 in)
198955.9 mm (2.2 in)
1990116.4 mm (4.6 in)
1991105.7 mm (4.2 in)
199283.3 mm (3.3 in)
1993123.4 mm (4.9 in)
199487.7 mm (3.5 in)
199581.3 mm (3.2 in)
199656.6 mm (2.2 in)
199798.1 mm (3.9 in)
1998162.5 mm (6.4 in)
1999158.2 mm (6.2 in)
200089.1 mm (3.5 in)
2001102.8 mm (4.0 in)
200261.1 mm (2.4 in)
200394.8 mm (3.7 in)
2004117.7 mm (4.6 in)
2005154.7 mm (6.1 in)
2006104.2 mm (4.1 in)
2007157.5 mm (6.2 in)
2008135.2 mm (5.3 in)
2009113.0 mm (4.4 in)
2010123.5 mm (4.9 in)
201183.0 mm (3.3 in)
201277.0 mm (3.0 in)
2013136.5 mm (5.4 in)
2014127.6 mm (5.0 in)
2015105.4 mm (4.1 in)
2016103.1 mm (4.1 in)
201776.9 mm (3.0 in)
2018196.5 mm (7.7 in)
201996.8 mm (3.8 in)
2020142.5 mm (5.6 in)
2021104.6 mm (4.1 in)
202266.7 mm (2.6 in)
202356.6 mm (2.2 in)
2024108.2 mm (4.3 in)
2025115.1 mm (4.5 in)
2026121.6 mm (4.8 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Waterloo Muni AP by year The longest dry spell of the year at Waterloo Muni AP, 1950 to 2026. The record is 45 days in 1999, marked on the chart; the median year is 23 days. 10203040501960198020002020Record: 45 days in 1999
The longest dry spell of the year at Waterloo Muni AP, 1950 to 2026. The record is 45 days in 1999, marked on the chart; the median year is 23 days.
Longest dry spell (CDD) at Waterloo Muni AP by year
YearLongest dry spell (CDD)
195029 days
195118 days
195241 days
195344 days
195434 days
195528 days
195633 days
195729 days
195834 days
195918 days
196016 days
196115 days
196234 days
196320 days
196423 days
196520 days
196621 days
196719 days
196838 days
196935 days
197020 days
197123 days
197216 days
197316 days
197415 days
197533 days
197633 days
197718 days
197820 days
197930 days
198030 days
198121 days
198216 days
198321 days
198421 days
198515 days
198623 days
198729 days
198842 days
198925 days
199018 days
199133 days
199221 days
199322 days
199426 days
199530 days
199622 days
199714 days
199819 days
199945 days
200025 days
200119 days
200235 days
200325 days
200418 days
200516 days
200617 days
200730 days
200814 days
200925 days
201027 days
201116 days
201221 days
201315 days
201423 days
201523 days
201626 days
201735 days
201823 days
201918 days
202037 days
202123 days
202222 days
202323 days
202432 days
202528 days
202617 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

75 years with a frost

Across 75 years with a frost, the median last spring frost at Waterloo Muni AP falls on 3 May and the median first autumn frost on 3 October, which leaves a median of 154 days between them.

In 1996 to 2025 the median growing season was 157 days. That is 4 days more than in 1951 to 1980.

Fitted over all years, the growing season changes by +1.0 days per decade at this station.

Frost dates and growing season at Waterloo Muni AP
MeasureMedian, all yearsEarliest period (1951 to 1980)Recent period (1996 to 2025)Recent against earliestFitted trend
Last spring frost3 May5 May3 May2 days earlier-0.2 days per decade
First autumn frost3 October1 October8 October7 days later+0.8 days per decade
Growing days154 days153 days157 days4 days more+1.0 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

75 years, 1951 to 2025

A day with at least 59.0 mm (2.3 in) of rain is expected about once in 2 years. A day with at least 135.1 mm (5.3 in) of rain is expected about once in 100 years.

Rainfall return levels at Waterloo Muni AP: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years59.0 mm (2.3 in)
5 years77.2 mm (3.0 in)
10 years90.0 mm (3.5 in)
25 years107.3 mm (4.2 in)
50 years120.9 mm (4.8 in)
100 years135.1 mm (5.3 in)Longer than the 75 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 75 years of values from 1951 to 2025.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 139.4 mm (5.5 in) in 1999; 134.9 mm (5.3 in) in 1968; 125.0 mm (4.9 in) in 1966.

Station Changes

2 suspected

2 changes were suspected in the annual mean temperature of Waterloo Muni AP, at 1960 and 1973. Each is measured against neighbouring stations.

  • Relative to 5 neighbouring stations, the station's annual mean temperature from 1960 ran 0.8 C (1.4 F) lower than in the years before (likely change).
  • Relative to 5 neighbouring stations, the station's annual mean temperature from 1973 ran 0.4 C (0.6 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Waterloo Muni AP, against neighbouring stations
YearShift (C)Shift (F)StrengthNeighbours
1960-0.8-1.4likely5
1973+0.4+0.6likely5

Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.

Climate Twins

2011 to 2025 against 1961 to 1990

Over 2011 to 2025, Waterloo Muni AP had a mean temperature of 9.3 C (48.8 F) and 899.6 mm (35.4 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Dixon Wwtp (United States, 251 km away), De Kalb (United States, 306 km away) and Kewanee 1E (United States, 253 km away).

Climate twins of Waterloo Muni AP: stations whose 1961 to 1990 climate is closest to its 2011 to 2025 climate
Twin stationCountryDistance awayMean temperature, 1961-1990Rain a year, 1961-1990Climate difference
Dixon WwtpUnited States251 km (156 mi)9.2 C (48.6 F)888.0 mm (35.0 in)0.70
De KalbUnited States306 km (190 mi)9.3 C (48.8 F)934.5 mm (36.8 in)0.75
Kewanee 1EUnited States253 km (157 mi)9.7 C (49.5 F)915.3 mm (36.0 in)0.79

Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.

Download the Data

  • Data for Waterloo Muni AP standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Waterloo Muni AP threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-12 (12 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-13).