Built 2026-10-15 (15 October 2026)

Boulder Rearing STN Weather Records (USC00480951)

Record envelope, standing records and threshold days for Boulder Rearing STN (USC00480951), Wyoming, United States, with 38 years of record.

Key Facts for Boulder Rearing STN

  • Boulder Rearing STN (USC00480951) is a weather station in Wyoming, United States at 42.72 latitude and -109.69 longitude, 2,115 m (6,940 ft) above sea level.
  • The station reports from 1989 to 2026, 38 years of record.
  • 1,464 records set at Boulder Rearing STN still stand.
  • Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Boulder Rearing STN set a monthly record high minimum temperature of 7.2 C (45.0 F) on 11 October 2026 (provisional).

Provisional Records

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

About the Station

  • Location: Wyoming, United States, 42.72 latitude, -109.69 longitude.
  • Elevation: 2,115 m (6,940 ft).
  • Period of record: 1989 to 2026, 38 years.
  • Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

54 days at or beyond a record
Daily record high and record low at Boulder Rearing STN, with 2026 drawn through them The band shows the record high and record low for each calendar day at Boulder Rearing STN. The lines show the 2026 daily maximum and minimum. 54 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -60-40-2002040 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Boulder Rearing STN. The lines show the 2026 daily maximum and minimum. 54 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Boulder Rearing STN, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan10.6 C (51.1 F)-42.2 C (-44.0 F)10.6 C (51.1 F)-23.9 C (-11.0 F)
Feb12.8 C (55.0 F)-38.9 C (-38.0 F)12.8 C (55.0 F)-23.3 C (-9.9 F)
Mar23.9 C (75.0 F)-33.9 C (-29.0 F)23.9 C (75.0 F)-17.2 C (1.0 F)
Apr25.0 C (77.0 F)-22.2 C (-8.0 F)21.7 C (71.1 F)-15.6 C (3.9 F)
May30.6 C (87.1 F)-12.8 C (9.0 F)28.3 C (82.9 F)-9.4 C (15.1 F)
Jun34.4 C (93.9 F)-7.8 C (18.0 F)29.4 C (84.9 F)-3.9 C (25.0 F)
Jul36.1 C (97.0 F)-3.9 C (25.0 F)36.1 C (97.0 F)0.6 C (33.1 F)
Aug33.9 C (93.0 F)-5.0 C (23.0 F)33.3 C (91.9 F)0.0 C (32.0 F)
Sep32.8 C (91.0 F)-11.1 C (12.0 F)27.2 C (81.0 F)-3.9 C (25.0 F)
Oct27.2 C (81.0 F)-27.2 C (-17.0 F)26.7 C (80.1 F)-3.9 C (25.0 F)
Nov19.4 C (66.9 F)-32.8 C (-27.0 F)n/an/a
Dec13.3 C (55.9 F)-46.7 C (-52.1 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Boulder Rearing STN by the year they were set 1,464 records at Boulder Rearing STN still stand. 1993 holds the most, with 59. 02040601989: 91990: 451991: 401992: 421993: 591994: 461995: 421996: 531997: 321998: 311999: 412000: 442001: 462002: 382003: 552004: 302005: 292006: 352007: 242008: 412009: 402010: 252011: 312012: 302013: 292014: 342015: 502016: 422017: 402018: 242019: 472020: 412021: 472022: 422023: 432024: 212025: 432026: 531989199319972001200520092013201720212025
1,464 records at Boulder Rearing STN still stand. 1993 holds the most, with 59.
Standing records at Boulder Rearing STN by the year they were set
Year setStanding records
19899
199045
199140
199242
199359
199446
199542
199653
199732
199831
199941
200044
200146
200238
200355
200430
200529
200635
200724
200841
200940
201025
201131
201230
201329
201434
201550
201642
201740
201824
201947
202041
202147
202242
202343
202421
202543
202653

All-Time Record Progression

7 new records
When Boulder Rearing STN set new all-time records 7 all-time records were set at Boulder Rearing STN between 23 February 2023 and 21 July 2026. Each dot is a new record. Record snow depthRecord high maximum temperatureRecord high minimum temperature23 February 2023: Record snow depth 66.0 cm (26.0 in)28 February 2023: Record snow depth 68.6 cm (27.0 in)6 March 2023: Record snow depth 76.2 cm (30.0 in)11 March 2023: Record snow depth 81.3 cm (32.0 in)13 July 2026: Record high maximum temperature 35.6 C (96.1 F)15 July 2026: Record high maximum temperature 36.1 C (97.0 F)21 July 2026: Record high minimum temperature 15.6 C (60.1 F)2025
7 all-time records were set at Boulder Rearing STN between 23 February 2023 and 21 July 2026. Each dot is a new record.
When Boulder Rearing STN set new all-time records
DateKindDetail
2023-02-23Record snow depthRecord snow depth 66.0 cm (26.0 in)
2023-02-28Record snow depthRecord snow depth 68.6 cm (27.0 in)
2023-03-06Record snow depthRecord snow depth 76.2 cm (30.0 in)
2023-03-11Record snow depthRecord snow depth 81.3 cm (32.0 in)
2026-07-13Record high maximum temperatureRecord high maximum temperature 35.6 C (96.1 F)
2026-07-15Record high maximum temperatureRecord high maximum temperature 36.1 C (97.0 F)
2026-07-21Record high minimum temperatureRecord high minimum temperature 15.6 C (60.1 F)

Wettest Day of Each Month

May: 43.2 mm (1.7 in)
Record daily precipitation for each month at Boulder Rearing STN The wettest day on record for each calendar month at Boulder Rearing STN. The most was 43.2 mm (1.7 in) on 27 May 1995. 0204060 Jan: 11.4 mm (0.4 in), 11 January 2023 Jan Feb: 15.2 mm (0.6 in), 14 February 1995 Feb Mar: 15.0 mm (0.6 in), 24 March 1996 Mar Apr: 26.2 mm (1.0 in), 22 April 2019 Apr May: 43.2 mm (1.7 in), 27 May 1995 May Jun: 37.6 mm (1.5 in), 9 June 1997 Jun Jul: 24.1 mm (0.9 in), 7 July 2015 Jul Aug: 29.5 mm (1.2 in), 5 August 1993 Aug Sep: 27.2 mm (1.1 in), 28 September 2014 Sep Oct: 27.4 mm (1.1 in), 17 October 2016 Oct Nov: 11.7 mm (0.5 in), 30 November 2019 Nov Dec: 10.7 mm (0.4 in), 9 December 2016 Dec
The wettest day on record for each calendar month at Boulder Rearing STN. The most was 43.2 mm (1.7 in) on 27 May 1995.
Record daily precipitation for each month at Boulder Rearing STN
MonthRecord daily precipitation (mm)Date
Jan11.4 mm (0.4 in)11 January 2023
Feb15.2 mm (0.6 in)14 February 1995
Mar15.0 mm (0.6 in)24 March 1996
Apr26.2 mm (1.0 in)22 April 2019
May43.2 mm (1.7 in)27 May 1995
Jun37.6 mm (1.5 in)9 June 1997
Jul24.1 mm (0.9 in)7 July 2015
Aug29.5 mm (1.2 in)5 August 1993
Sep27.2 mm (1.1 in)28 September 2014
Oct27.4 mm (1.1 in)17 October 2016
Nov11.7 mm (0.5 in)30 November 2019
Dec10.7 mm (0.4 in)9 December 2016

Period of Record Coverage

1989 to 2026
Days with data per year at Boulder Rearing STN 38 years of record at Boulder Rearing STN, 1989 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1989, 2026. 1989: 122 of 365 days1990: 363 of 365 days1991: 365 of 365 days1992: 363 of 366 days1993: 364 of 365 days1994: 365 of 365 days1995: 365 of 365 days1996: 365 of 366 days1997: 363 of 365 days1998: 363 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: 362 of 365 days2006: 361 of 365 days2007: 360 of 365 days2008: 349 of 366 days2009: 358 of 365 days2010: 363 of 365 days2011: 364 of 365 days2012: 366 of 366 days2013: 361 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: 364 of 365 days2023: 365 of 365 days2024: 365 of 366 days2025: 364 of 365 days2026: 284 of 365 days19901995200020052010201520202025
38 years of record at Boulder Rearing STN, 1989 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1989, 2026.
Days with data per year at Boulder Rearing STN
YearDays with dataShare of yearComplete
198912233%No
199036399%Yes
1991365100%Yes
199236399%Yes
1993364100%Yes
1994365100%Yes
1995365100%Yes
1996365100%Yes
199736399%Yes
199836399%Yes
1999365100%Yes
2000366100%Yes
2001365100%Yes
2002365100%Yes
2003365100%Yes
2004366100%Yes
200536299%Yes
200636199%Yes
200736099%Yes
200834995%Yes
200935898%Yes
201036399%Yes
2011364100%Yes
2012366100%Yes
201336199%Yes
2014365100%Yes
2015365100%Yes
2016366100%Yes
2017365100%Yes
2018365100%Yes
2019365100%Yes
2020366100%Yes
2021365100%Yes
2022364100%Yes
2023365100%Yes
2024365100%Yes
2025364100%Yes
202628478%No

Latest Records

20
Latest records at Boulder Rearing STN
DateStationRecordValueBeat old record byOld record stoodSignificance
11 October 2026Boulder Rearing STN, USmonthly high min (Provisional)7.2 C (45.0 F)0.5 C (0.9 F)8 years16 of 100 (Routine)
9 October 2026Boulder Rearing STN, USdaily high max (Provisional)25.6 C (78.1 F)0.6 C (1.1 F)5 years4 of 100 (Routine)
8 October 2026Boulder Rearing STN, USdaily high max (Provisional)26.1 C (79.0 F)2.2 C (4.0 F)29 years14 of 100 (Routine)
7 October 2026Boulder Rearing STN, USdaily high max (Tie, Provisional)26.1 C (79.0 F)tie5 years1 of 100 (Routine)
6 October 2026Boulder Rearing STN, USdaily high max (Provisional)26.7 C (80.1 F)2.8 C (5.0 F)32 years16 of 100 (Routine)
5 October 2026Boulder Rearing STN, USdaily high max (Tie, Provisional)26.1 C (79.0 F)tie1 year0 of 100 (Routine)
17 September 2026Boulder Rearing STN, USdaily high min (Provisional)8.3 C (46.9 F)1.1 C (2.0 F)7 years7 of 100 (Routine)
30 August 2026Boulder Rearing STN, USdaily low max (Provisional)20.0 C (68.0 F)0.6 C (1.1 F)32 years13 of 100 (Routine)
29 August 2026Boulder Rearing STN, USdaily high min (Provisional)12.2 C (54.0 F)4.4 C (7.9 F)28 years24 of 100 (Routine)
29 August 2026Boulder Rearing STN, USdaily rain (Provisional)2.8 mm (0.11 in)2.3 mm (0.09 in)15 years12 of 100 (Routine)
28 August 2026Boulder Rearing STN, USdaily high min (Provisional)10.0 C (50.0 F)0.6 C (1.1 F)35 years14 of 100 (Routine)
25 August 2026Boulder Rearing STN, USdaily rain (Provisional)3.8 mm (0.15 in)1.3 mm (0.05 in)21 years12 of 100 (Routine)
22 August 2026Boulder Rearing STN, USdaily high max (Tie, Provisional)30.6 C (87.1 F)tie23 years2 of 100 (Routine)
14 August 2026Boulder Rearing STN, USdaily rain9.4 mm (0.37 in)6.1 mm (0.24 in)12 years20 of 100 (Routine)
14 August 2026Boulder Rearing STN, USdaily low max19.4 C (66.9 F)1.7 C (3.1 F)20 years14 of 100 (Routine)
10 August 2026Boulder Rearing STN, USdaily high max31.7 C (89.1 F)0.6 C (1.1 F)25 years11 of 100 (Routine)
6 August 2026Boulder Rearing STN, USdaily low min (Tie)1.1 C (34.0 F)tie8 years1 of 100 (Routine)
3 August 2026Boulder Rearing STN, USdaily high max33.3 C (91.9 F)1.1 C (2.0 F)25 years13 of 100 (Routine)
2 August 2026Boulder Rearing STN, USdaily high max32.8 C (91.0 F)0.6 C (1.1 F)25 years11 of 100 (Routine)
27 July 2026Boulder Rearing STN, USdaily high min12.8 C (55.0 F)1.7 C (3.1 F)19 years13 of 100 (Routine)

Climate Trend

35 complete years, 1990 to 2025
Annual mean temperature at Boulder Rearing STN as warming stripes, 1990 to 2025 One stripe for each of 35 complete years at Boulder Rearing STN, 1990 to 2025. Blue stripes are years cooler than the station's own mean of 2.5 C (36.6 F); red stripes are warmer. The coolest year was 1993, at 0.6 C (33.2 F), and the warmest was 2025, at 4.1 C (39.4 F). The strongest colour marks a difference of 1.9 C (3.4 F). 1990: 2.4 C, -0.1 C from the station mean1991: 2.0 C, -0.5 C from the station mean1992: 2.8 C, +0.2 C from the station mean1993: 0.6 C, -1.9 C from the station mean1994: 3.4 C, +0.9 C from the station mean1995: 2.9 C, +0.4 C from the station mean1996: 2.3 C, -0.3 C from the station mean1997: 2.1 C, -0.5 C from the station mean1998: 2.5 C, 0.0 C from the station mean1999: 3.1 C, +0.6 C from the station mean2000: 2.6 C, 0.0 C from the station mean2001: 2.6 C, +0.1 C from the station mean2002: 1.7 C, -0.8 C from the station mean2003: 2.7 C, +0.1 C from the station mean2004: 2.1 C, -0.5 C from the station mean2005: 2.2 C, -0.3 C from the station mean2006: 2.2 C, -0.3 C from the station mean2007: 3.2 C, +0.7 C from the station mean2009: 2.0 C, -0.5 C from the station mean2010: 2.6 C, 0.0 C from the station mean2011: 1.3 C, -1.2 C from the station mean2012: 3.4 C, +0.8 C from the station mean2013: 2.4 C, -0.2 C from the station mean2014: 3.0 C, +0.5 C from the station mean2015: 3.7 C, +1.2 C from the station mean2016: 3.5 C, +0.9 C from the station mean2017: 2.9 C, +0.3 C from the station mean2018: 3.0 C, +0.5 C from the station mean2019: 0.9 C, -1.6 C from the station mean2020: 2.1 C, -0.4 C from the station mean2021: 3.5 C, +0.9 C from the station mean2022: 2.1 C, -0.4 C from the station mean2023: 1.5 C, -1.1 C from the station mean2024: 3.7 C, +1.1 C from the station mean2025: 4.1 C, +1.6 C from the station mean19901995200020052010201520202025
One stripe for each of 35 complete years at Boulder Rearing STN, 1990 to 2025. Blue stripes are years cooler than the station's own mean of 2.5 C (36.6 F); red stripes are warmer. The coolest year was 1993, at 0.6 C (33.2 F), and the warmest was 2025, at 4.1 C (39.4 F). The strongest colour marks a difference of 1.9 C (3.4 F).
Annual mean temperature at Boulder Rearing STN as warming stripes, 1990 to 2025
YearAnnual mean temperatureDifference from the station mean
19902.4 C-0.09 C
19912.0 C-0.53 C
19922.8 C+0.23 C
19930.6 C-1.89 C
19943.4 C+0.89 C
19952.9 C+0.37 C
19962.3 C-0.27 C
19972.1 C-0.48 C
19982.5 C-0.04 C
19993.1 C+0.57 C
20002.6 C+0.02 C
20012.6 C+0.08 C
20021.7 C-0.83 C
20032.7 C+0.13 C
20042.1 C-0.48 C
20052.2 C-0.33 C
20062.2 C-0.30 C
20073.2 C+0.68 C
20092.0 C-0.54 C
20102.6 C+0.04 C
20111.3 C-1.19 C
20123.4 C+0.85 C
20132.4 C-0.18 C
20143.0 C+0.46 C
20153.7 C+1.16 C
20163.5 C+0.92 C
20172.9 C+0.34 C
20183.0 C+0.47 C
20190.9 C-1.62 C
20202.1 C-0.42 C
20213.5 C+0.95 C
20222.1 C-0.44 C
20231.5 C-1.08 C
20243.7 C+1.13 C
20254.1 C+1.58 C

The fitted trend in annual mean temperature here over 1990 to 2025 is 0.2 C (-0.1 to 0.4) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.3 F (-0.2 to 0.8) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Boulder Rearing STN
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.2 C (-0.1 to 0.4) per decade0.3 F (-0.2 to 0.8) per decade1990 to 202535Not clearly different from zero
Mean daily maximum0.4 C (0.1 to 0.7) per decade0.7 F (0.1 to 1.2) per decade1990 to 202535Rise
Mean daily minimum-0.04 C (-0.29 to 0.22) per decade-0.1 F (-0.5 to 0.4) per decade1990 to 202535Not clearly different from zero

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

1989 to 2026
Yearly extremes at Boulder Rearing STN: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)36.1 C (97.0 F)202632.2 C (90.0 F)38
Coldest night (TNn)-46.7 C (-52.1 F)1990-34.7 C (-30.5 F)38
Wettest day (Rx1day)43.2 mm (1.7 in)199519.2 mm (0.8 in)38
Wettest five days (Rx5day)56.1 mm (2.2 in)199529.9 mm (1.2 in)38
Longest dry spell (CDD)62 days200835 days38

Hottest day (TXx)

Hottest day (TXx) at Boulder Rearing STN by year The hottest day of the year at Boulder Rearing STN, 1989 to 2026. The record is 36.1 C (97.0 F) in 2026, marked on the chart; the median year is 32.2 C (90.0 F). 2527.53032.53537.51990200020102020Record: 36.1 C (97.0 F) in 2026
The hottest day of the year at Boulder Rearing STN, 1989 to 2026. The record is 36.1 C (97.0 F) in 2026, marked on the chart; the median year is 32.2 C (90.0 F).
Hottest day (TXx) at Boulder Rearing STN by year
YearHottest day (TXx)
198926.7 C (80.1 F)
199032.2 C (90.0 F)
199130.6 C (87.1 F)
199231.7 C (89.1 F)
199327.8 C (82.0 F)
199432.2 C (90.0 F)
199531.7 C (89.1 F)
199631.1 C (88.0 F)
199731.1 C (88.0 F)
199833.3 C (91.9 F)
199930.6 C (87.1 F)
200032.8 C (91.0 F)
200133.9 C (93.0 F)
200234.4 C (93.9 F)
200333.3 C (91.9 F)
200430.6 C (87.1 F)
200533.3 C (91.9 F)
200633.3 C (91.9 F)
200733.3 C (91.9 F)
200831.1 C (88.0 F)
200931.1 C (88.0 F)
201031.1 C (88.0 F)
201131.1 C (88.0 F)
201232.2 C (90.0 F)
201332.2 C (90.0 F)
201431.7 C (89.1 F)
201534.4 C (93.9 F)
201631.7 C (89.1 F)
201731.1 C (88.0 F)
201833.3 C (91.9 F)
201931.7 C (89.1 F)
202032.8 C (91.0 F)
202133.9 C (93.0 F)
202233.3 C (91.9 F)
202332.8 C (91.0 F)
202433.3 C (91.9 F)
202532.8 C (91.0 F)
202636.1 C (97.0 F)

Coldest night (TNn)

Coldest night (TNn) at Boulder Rearing STN by year The coldest night of the year at Boulder Rearing STN, 1989 to 2026. The record is -46.7 C (-52.1 F) in 1990, marked on the chart; the median year is -34.7 C (-30.5 F). -50-40-30-201990200020102020Record: -46.7 C (-52.1 F) in 1990
The coldest night of the year at Boulder Rearing STN, 1989 to 2026. The record is -46.7 C (-52.1 F) in 1990, marked on the chart; the median year is -34.7 C (-30.5 F).
Coldest night (TNn) at Boulder Rearing STN by year
YearColdest night (TNn)
1989-31.1 C (-24.0 F)
1990-46.7 C (-52.1 F)
1991-33.9 C (-29.0 F)
1992-37.2 C (-35.0 F)
1993-37.8 C (-36.0 F)
1994-33.3 C (-27.9 F)
1995-34.4 C (-29.9 F)
1996-38.3 C (-36.9 F)
1997-33.3 C (-27.9 F)
1998-37.8 C (-36.0 F)
1999-28.9 C (-20.0 F)
2000-30.0 C (-22.0 F)
2001-33.3 C (-27.9 F)
2002-37.2 C (-35.0 F)
2003-31.7 C (-25.1 F)
2004-34.4 C (-29.9 F)
2005-38.3 C (-36.9 F)
2006-35.6 C (-32.1 F)
2007-37.2 C (-35.0 F)
2008-37.8 C (-36.0 F)
2009-37.2 C (-35.0 F)
2010-31.7 C (-25.1 F)
2011-38.9 C (-38.0 F)
2012-31.1 C (-24.0 F)
2013-36.7 C (-34.1 F)
2014-37.2 C (-35.0 F)
2015-36.7 C (-34.1 F)
2016-31.1 C (-24.0 F)
2017-42.2 C (-44.0 F)
2018-32.2 C (-26.0 F)
2019-35.0 C (-31.0 F)
2020-33.9 C (-29.0 F)
2021-30.6 C (-23.1 F)
2022-34.4 C (-29.9 F)
2023-40.6 C (-41.1 F)
2024-32.8 C (-27.0 F)
2025-35.6 C (-32.1 F)
2026-23.9 C (-11.0 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Boulder Rearing STN by year The wettest day of the year at Boulder Rearing STN, 1989 to 2026. The record is 43.2 mm (1.7 in) in 1995, marked on the chart; the median year is 19.2 mm (0.8 in). 10203040501990200020102020Record: 43.2 mm (1.7 in) in 1995
The wettest day of the year at Boulder Rearing STN, 1989 to 2026. The record is 43.2 mm (1.7 in) in 1995, marked on the chart; the median year is 19.2 mm (0.8 in).
Wettest day (Rx1day) at Boulder Rearing STN by year
YearWettest day (Rx1day)
198910.4 mm (0.4 in)
199018.3 mm (0.7 in)
199123.1 mm (0.9 in)
199215.7 mm (0.6 in)
199329.5 mm (1.2 in)
199415.5 mm (0.6 in)
199543.2 mm (1.7 in)
199615.0 mm (0.6 in)
199737.6 mm (1.5 in)
199822.1 mm (0.9 in)
199919.8 mm (0.8 in)
200013.5 mm (0.5 in)
200111.4 mm (0.4 in)
200218.8 mm (0.7 in)
200312.7 mm (0.5 in)
200422.9 mm (0.9 in)
200521.1 mm (0.8 in)
200616.3 mm (0.6 in)
200716.3 mm (0.6 in)
200821.6 mm (0.9 in)
200919.3 mm (0.8 in)
201016.3 mm (0.6 in)
201114.2 mm (0.6 in)
201219.8 mm (0.8 in)
201314.0 mm (0.6 in)
201427.2 mm (1.1 in)
201524.1 mm (0.9 in)
201627.4 mm (1.1 in)
201719.1 mm (0.8 in)
201833.5 mm (1.3 in)
201926.2 mm (1.0 in)
202021.3 mm (0.8 in)
202122.9 mm (0.9 in)
202222.9 mm (0.9 in)
202316.3 mm (0.6 in)
202411.7 mm (0.5 in)
202518.5 mm (0.7 in)
202614.0 mm (0.6 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Boulder Rearing STN by year The wettest five days of the year at Boulder Rearing STN, 1989 to 2026. The record is 56.1 mm (2.2 in) in 1995, marked on the chart; the median year is 29.9 mm (1.2 in). 02040601990200020102020Record: 56.1 mm (2.2 in) in 1995
The wettest five days of the year at Boulder Rearing STN, 1989 to 2026. The record is 56.1 mm (2.2 in) in 1995, marked on the chart; the median year is 29.9 mm (1.2 in).
Wettest five days (Rx5day) at Boulder Rearing STN by year
YearWettest five days (Rx5day)
198915.8 mm (0.6 in)
199041.7 mm (1.6 in)
199128.4 mm (1.1 in)
199224.6 mm (1.0 in)
199351.1 mm (2.0 in)
199425.1 mm (1.0 in)
199556.1 mm (2.2 in)
199628.5 mm (1.1 in)
199741.9 mm (1.6 in)
199838.7 mm (1.5 in)
199931.3 mm (1.2 in)
200021.9 mm (0.9 in)
200112.2 mm (0.5 in)
200235.8 mm (1.4 in)
200331.9 mm (1.3 in)
200442.5 mm (1.7 in)
200536.0 mm (1.4 in)
200620.9 mm (0.8 in)
200724.7 mm (1.0 in)
200843.2 mm (1.7 in)
200939.1 mm (1.5 in)
201026.1 mm (1.0 in)
201117.5 mm (0.7 in)
201227.2 mm (1.1 in)
201326.4 mm (1.0 in)
201451.6 mm (2.0 in)
201534.5 mm (1.4 in)
201631.2 mm (1.2 in)
201734.8 mm (1.4 in)
201841.9 mm (1.6 in)
201928.5 mm (1.1 in)
202033.2 mm (1.3 in)
202145.0 mm (1.8 in)
202222.9 mm (0.9 in)
202326.7 mm (1.1 in)
202419.0 mm (0.7 in)
202524.6 mm (1.0 in)
202618.3 mm (0.7 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Boulder Rearing STN by year The longest dry spell of the year at Boulder Rearing STN, 1989 to 2026. The record is 62 days in 2008, marked on the chart; the median year is 35 days. 2030405060701990200020102020Record: 62 days in 2008
The longest dry spell of the year at Boulder Rearing STN, 1989 to 2026. The record is 62 days in 2008, marked on the chart; the median year is 35 days.
Longest dry spell (CDD) at Boulder Rearing STN by year
YearLongest dry spell (CDD)
198934 days
199038 days
199137 days
199261 days
199333 days
199431 days
199530 days
199641 days
199733 days
199825 days
199952 days
200025 days
200127 days
200260 days
200327 days
200438 days
200528 days
200643 days
200728 days
200862 days
200945 days
201040 days
201134 days
201241 days
201335 days
201439 days
201536 days
201636 days
201726 days
201836 days
201923 days
202053 days
202134 days
202234 days
202333 days
202429 days
202528 days
202643 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

35 years with a frost

Across 35 years with a frost, the median last spring frost at Boulder Rearing STN falls on 23 June and the median first autumn frost on 12 August, which leaves a median of 58 days between them.

Fitted over all years, the growing season changes by +3.4 days per decade at this station.

Frost dates and growing season at Boulder Rearing STN
MeasureMedian, all yearsEarliest periodRecent period (1995 to 2025)Recent against earliestFitted trend
Last spring frost23 Junen/a23 Junen/a-0.7 days per decade
First autumn frost12 Augustn/a11 Augustn/a+2.7 days per decade
Growing days58 daysn/a56 daysn/a+3.4 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

36 years, 1990 to 2025

A day with at least 19.3 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 46.0 mm (1.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Boulder Rearing STN: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years19.3 mm (0.8 in)
5 years25.4 mm (1.0 in)
10 years29.9 mm (1.2 in)
25 years36.0 mm (1.4 in)
50 years40.9 mm (1.6 in)Longer than the 36 years of record
100 years46.0 mm (1.8 in)Longer than the 36 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, 36 years of values from 1990 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: 43.2 mm (1.7 in) in 1995; 37.6 mm (1.5 in) in 1997; 33.5 mm (1.3 in) in 2018.

Download the Data

  • Data for Boulder Rearing STN standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Boulder Rearing STN 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.

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