Built 2026-10-19 (19 October 2026)

Mill Creek Summit Weather Records (USS0014E01S)

Record envelope, standing records and threshold days for Mill Creek Summit (USS0014E01S), Idaho, United States, with 48 years of record.

Key Facts for Mill Creek Summit

  • Mill Creek Summit (USS0014E01S) is a weather station in Idaho, United States at 44.47 latitude and -114.49 longitude, 2,682 m (8,800 ft) above sea level.
  • The station reports from 1979 to 2026, 48 years of record.
  • 1,464 records set at Mill Creek Summit still stand.
  • Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
  • Mill Creek Summit set a daily record high maximum temperature of 17.8 C (64.0 F) on 8 October 2026 (provisional).

Provisional Records

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

About the Station

  • Location: Idaho, United States, 44.47 latitude, -114.49 longitude.
  • Elevation: 2,682 m (8,800 ft).
  • Period of record: 1979 to 2026, 48 years.
  • Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

20 days at or beyond a record
Daily record high and record low at Mill Creek Summit, with 2026 drawn through them The band shows the record high and record low for each calendar day at Mill Creek Summit. The lines show the 2026 daily maximum and minimum. 20 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -40-2002040 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Mill Creek Summit. The lines show the 2026 daily maximum and minimum. 20 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Mill Creek Summit, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan11.9 C (53.4 F)-30.1 C (-22.2 F)9.2 C (48.6 F)-18.3 C (-0.9 F)
Feb13.0 C (55.4 F)-28.8 C (-19.8 F)11.0 C (51.8 F)-22.5 C (-8.5 F)
Mar16.7 C (62.1 F)-26.0 C (-14.8 F)13.2 C (55.8 F)-16.2 C (2.8 F)
Apr19.7 C (67.5 F)-21.1 C (-6.0 F)16.4 C (61.5 F)-15.3 C (4.5 F)
May24.0 C (75.2 F)-16.1 C (3.0 F)21.1 C (70.0 F)-11.5 C (11.3 F)
Jun28.4 C (83.1 F)-9.4 C (15.1 F)23.7 C (74.7 F)-6.8 C (19.8 F)
Jul31.0 C (87.8 F)-5.0 C (23.0 F)27.2 C (81.0 F)0.6 C (33.1 F)
Aug29.9 C (85.8 F)-9.3 C (15.3 F)26.7 C (80.1 F)-0.8 C (30.6 F)
Sep27.3 C (81.1 F)-14.0 C (6.8 F)18.7 C (65.7 F)-3.1 C (26.4 F)
Oct23.5 C (74.3 F)-24.1 C (-11.4 F)20.1 C (68.2 F)-6.2 C (20.8 F)
Nov13.7 C (56.7 F)-27.4 C (-17.3 F)n/an/a
Dec10.8 C (51.4 F)-33.9 C (-29.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Mill Creek Summit by the year they were set 1,464 records at Mill Creek Summit still stand. 1996 holds the most, with 62. 0204060801989: 121990: 391991: 251992: 331993: 521994: 461995: 351996: 621997: 291998: 181999: 392000: 352001: 332002: 522003: 542004: 262005: 292006: 362007: 342008: 532009: 472010: 472011: 282012: 372013: 392014: 342015: 552016: 362017: 362018: 242019: 282020: 492021: 422022: 512023: 412024: 392025: 502026: 391989199319972001200520092013201720212025
1,464 records at Mill Creek Summit still stand. 1996 holds the most, with 62.
Standing records at Mill Creek Summit by the year they were set
Year setStanding records
198912
199039
199125
199233
199352
199446
199535
199662
199729
199818
199939
200035
200133
200252
200354
200426
200529
200636
200734
200853
200947
201047
201128
201237
201339
201434
201555
201636
201736
201824
201928
202049
202142
202251
202341
202439
202550
202639

All-Time Record Progression

1 new records
When Mill Creek Summit set new all-time records 1 all-time records were set at Mill Creek Summit between 17 July 2022 and 17 July 2022. Each dot is a new record. Record high minimum temperature17 July 2022: Record high minimum temperature 13.8 C (56.8 F)
1 all-time records were set at Mill Creek Summit between 17 July 2022 and 17 July 2022. Each dot is a new record.
When Mill Creek Summit set new all-time records
DateKindDetail
2022-07-17Record high minimum temperatureRecord high minimum temperature 13.8 C (56.8 F)

Wettest Day of Each Month

Jan: 55.9 mm (2.2 in)
Record daily precipitation for each month at Mill Creek Summit The wettest day on record for each calendar month at Mill Creek Summit. The most was 55.9 mm (2.2 in) on 1 January 1997. 0204060 Jan: 55.9 mm (2.2 in), 1 January 1997 Jan Feb: 38.1 mm (1.5 in), 18 February 1986 Feb Mar: 35.6 mm (1.4 in), 8 March 2017 Mar Apr: 27.9 mm (1.1 in), 20 April 2001 Apr May: 33.0 mm (1.3 in), 6 May 1986 May Jun: 35.6 mm (1.4 in), 6 June 1993 Jun Jul: 55.9 mm (2.2 in), 9 July 1983 Jul Aug: 30.5 mm (1.2 in), 19 August 1990 Aug Sep: 33.0 mm (1.3 in), 11 September 1997 Sep Oct: 35.6 mm (1.4 in), 19 October 2007 Oct Nov: 48.3 mm (1.9 in), 2 November 1984 Nov Dec: 48.3 mm (1.9 in), 12 December 1995 Dec
The wettest day on record for each calendar month at Mill Creek Summit. The most was 55.9 mm (2.2 in) on 1 January 1997.
Record daily precipitation for each month at Mill Creek Summit
MonthRecord daily precipitation (mm)Date
Jan55.9 mm (2.2 in)1 January 1997
Feb38.1 mm (1.5 in)18 February 1986
Mar35.6 mm (1.4 in)8 March 2017
Apr27.9 mm (1.1 in)20 April 2001
May33.0 mm (1.3 in)6 May 1986
Jun35.6 mm (1.4 in)6 June 1993
Jul55.9 mm (2.2 in)9 July 1983
Aug30.5 mm (1.2 in)19 August 1990
Sep33.0 mm (1.3 in)11 September 1997
Oct35.6 mm (1.4 in)19 October 2007
Nov48.3 mm (1.9 in)2 November 1984
Dec48.3 mm (1.9 in)12 December 1995

Period of Record Coverage

1989 to 2026
Days with data per year at Mill Creek Summit 38 years of record at Mill Creek Summit, 1989 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1989, 2026. 1989: 194 of 365 days1990: 362 of 365 days1991: 363 of 365 days1992: 366 of 366 days1993: 340 of 365 days1994: 354 of 365 days1995: 365 of 365 days1996: 366 of 366 days1997: 363 of 365 days1998: 365 of 365 days1999: 364 of 365 days2000: 363 of 366 days2001: 365 of 365 days2002: 365 of 365 days2003: 365 of 365 days2004: 366 of 366 days2005: 365 of 365 days2006: 364 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: 360 of 365 days2023: 365 of 365 days2024: 366 of 366 days2025: 364 of 365 days2026: 286 of 365 days19901995200020052010201520202025
38 years of record at Mill Creek Summit, 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 Mill Creek Summit
YearDays with dataShare of yearComplete
198919453%No
199036299%Yes
199136399%Yes
1992366100%Yes
199334093%Yes
199435497%Yes
1995365100%Yes
1996366100%Yes
199736399%Yes
1998365100%Yes
1999364100%Yes
200036399%Yes
2001365100%Yes
2002365100%Yes
2003365100%Yes
2004366100%Yes
2005365100%Yes
2006364100%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
202236099%Yes
2023365100%Yes
2024366100%Yes
2025364100%Yes
202628678%No

Latest Records

20
Latest records at Mill Creek Summit
DateStationRecordValueBeat old record byOld record stoodSignificance
8 October 2026Mill Creek Summit, USdaily high max (Provisional)17.8 C (64.0 F)0.1 C (0.2 F)29 years11 of 100 (Routine)
8 October 2026Mill Creek Summit, USdaily high min (Provisional)6.0 C (42.8 F)1.9 C (3.4 F)1 year6 of 100 (Routine)
7 October 2026Mill Creek Summit, USdaily high min (Provisional)6.0 C (42.8 F)2.3 C (4.1 F)23 years13 of 100 (Routine)
7 October 2026Mill Creek Summit, USdaily high max (Provisional)19.1 C (66.4 F)1.1 C (2.0 F)29 years12 of 100 (Routine)
6 October 2026Mill Creek Summit, USdaily high min (Provisional)6.2 C (43.2 F)1.5 C (2.7 F)12 years8 of 100 (Routine)
5 October 2026Mill Creek Summit, USdaily high max (Provisional)20.1 C (68.2 F)2.7 C (4.9 F)4 years8 of 100 (Routine)
5 October 2026Mill Creek Summit, USdaily high min (Provisional)7.6 C (45.7 F)1.4 C (2.5 F)4 years6 of 100 (Routine)
4 October 2026Mill Creek Summit, USdaily high max (Provisional)19.5 C (67.1 F)1.2 C (2.2 F)29 years12 of 100 (Routine)
4 October 2026Mill Creek Summit, USdaily high min (Provisional)4.8 C (40.6 F)0.2 C (0.4 F)1 year3 of 100 (Routine)
17 September 2026Mill Creek Summit, USdaily rain (Tie, Provisional)10.2 mm (0.4 in)tie36 years3 of 100 (Routine)
4 September 2026Mill Creek Summit, USall-time rain (Provisional)58.4 mm (2.3 in)2.5 mm (0.10 in)43 years40 of 100 (Notable)
28 August 2026Mill Creek Summit, USdaily high min (Provisional)9.2 C (48.6 F)0.1 C (0.2 F)15 years7 of 100 (Routine)
21 August 2026Mill Creek Summit, USdaily high min (Provisional)11.5 C (52.7 F)0.9 C (1.6 F)23 years11 of 100 (Routine)
20 August 2026Mill Creek Summit, USdaily high max (Provisional)26.5 C (79.7 F)0.4 C (0.7 F)16 years8 of 100 (Routine)
14 August 2026Mill Creek Summit, USdaily rain5.1 mm (0.20 in)2.6 mm (0.10 in)32 years18 of 100 (Routine)
1 August 2026Mill Creek Summit, USdaily high min11.8 C (53.2 F)0.2 C (0.4 F)25 years10 of 100 (Routine)
26 July 2026Mill Creek Summit, USdaily high min11.1 C (52.0 F)1.5 C (2.7 F)4 years8 of 100 (Routine)
25 July 2026Mill Creek Summit, USdaily high min12.2 C (54.0 F)2.0 C (3.6 F)8 years10 of 100 (Routine)
22 July 2026Mill Creek Summit, USall-time rain (Tie)55.9 mm (2.2 in)tie43 years9 of 100 (Routine)
21 July 2026Mill Creek Summit, USdaily high min10.7 C (51.3 F)0.2 C (0.4 F)23 years9 of 100 (Routine)

Climate Trend

36 complete years, 1990 to 2025
Annual mean temperature at Mill Creek Summit as warming stripes, 1990 to 2025 One stripe for each of 36 complete years at Mill Creek Summit, 1990 to 2025. Blue stripes are years cooler than the station's own mean of 1.1 C (33.9 F); red stripes are warmer. The coolest year was 1993, at -0.2 C (31.7 F), and the warmest was 2015, at 2.3 C (36.2 F). The strongest colour marks a difference of 1.3 C (2.3 F). 1990: 0.5 C, -0.6 C from the station mean1991: 0.8 C, -0.3 C from the station mean1992: 1.5 C, +0.4 C from the station mean1993: -0.2 C, -1.2 C from the station mean1994: 1.0 C, -0.1 C from the station mean1995: 0.7 C, -0.4 C from the station mean1996: 0.5 C, -0.6 C from the station mean1997: 0.4 C, -0.7 C from the station mean1998: 0.7 C, -0.4 C from the station mean1999: 0.9 C, -0.1 C from the station mean2000: 1.0 C, 0.0 C from the station mean2001: 1.3 C, +0.3 C from the station mean2002: 0.7 C, -0.4 C from the station mean2003: 1.5 C, +0.5 C from the station mean2004: 1.3 C, +0.2 C from the station mean2005: 1.4 C, +0.3 C from the station mean2006: 1.1 C, 0.0 C from the station mean2007: 1.6 C, +0.5 C from the station mean2008: 0.4 C, -0.6 C from the station mean2009: 0.4 C, -0.6 C from the station mean2010: 0.5 C, -0.6 C from the station mean2011: 0.2 C, -0.9 C from the station mean2012: 1.5 C, +0.4 C from the station mean2013: 1.2 C, +0.1 C from the station mean2014: 1.4 C, +0.4 C from the station mean2015: 2.3 C, +1.3 C from the station mean2016: 1.6 C, +0.6 C from the station mean2017: 1.3 C, +0.3 C from the station mean2018: 1.2 C, +0.1 C from the station mean2019: 0.5 C, -0.5 C from the station mean2020: 1.4 C, +0.3 C from the station mean2021: 1.6 C, +0.5 C from the station mean2022: 1.0 C, 0.0 C from the station mean2023: 1.0 C, 0.0 C from the station mean2024: 1.9 C, +0.8 C from the station mean2025: 2.3 C, +1.2 C from the station mean19901995200020052010201520202025
One stripe for each of 36 complete years at Mill Creek Summit, 1990 to 2025. Blue stripes are years cooler than the station's own mean of 1.1 C (33.9 F); red stripes are warmer. The coolest year was 1993, at -0.2 C (31.7 F), and the warmest was 2015, at 2.3 C (36.2 F). The strongest colour marks a difference of 1.3 C (2.3 F).
Annual mean temperature at Mill Creek Summit as warming stripes, 1990 to 2025
YearAnnual mean temperatureDifference from the station mean
19900.5 C-0.59 C
19910.8 C-0.31 C
19921.5 C+0.41 C
1993-0.2 C-1.24 C
19941.0 C-0.08 C
19950.7 C-0.40 C
19960.5 C-0.61 C
19970.4 C-0.68 C
19980.7 C-0.36 C
19990.9 C-0.13 C
20001.0 C-0.04 C
20011.3 C+0.26 C
20020.7 C-0.40 C
20031.5 C+0.46 C
20041.3 C+0.21 C
20051.4 C+0.28 C
20061.1 C+0.01 C
20071.6 C+0.48 C
20080.4 C-0.64 C
20090.4 C-0.63 C
20100.5 C-0.62 C
20110.2 C-0.89 C
20121.5 C+0.41 C
20131.2 C+0.14 C
20141.4 C+0.35 C
20152.3 C+1.25 C
20161.6 C+0.56 C
20171.3 C+0.26 C
20181.2 C+0.12 C
20190.5 C-0.53 C
20201.4 C+0.34 C
20211.6 C+0.54 C
20221.0 C-0.03 C
20231.0 C-0.04 C
20241.9 C+0.84 C
20252.3 C+1.19 C

The annual mean temperature here has risen by 0.3 C (0.1 to 0.4) per decade over 1990 to 2025. In Fahrenheit: 0.5 F (0.2 to 0.8) per decade. The slope is a straight line fitted to 36 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Mill Creek Summit
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.3 C (0.1 to 0.4) per decade0.5 F (0.2 to 0.8) per decade1990 to 202536Rise
Mean daily maximum0.18 C (-0.01 to 0.36) per decade0.32 F (-0.01 to 0.64) per decade1990 to 202536Not clearly different from zero
Mean daily minimum0.4 C (0.2 to 0.5) per decade0.7 F (0.4 to 0.9) per decade1990 to 202536Rise

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

1979 to 2026
Yearly extremes at Mill Creek Summit: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)31.0 C (87.8 F)200027.3 C (81.1 F)38
Coldest night (TNn)-33.9 C (-29.0 F)1990-25.6 C (-14.2 F)38
Wettest day (Rx1day)58.4 mm (2.3 in)202630.5 mm (1.2 in)47
Wettest five days (Rx5day)172.7 mm (6.8 in)199761.0 mm (2.4 in)46
Longest dry spell (CDD)91 days198825 days47

Hottest day (TXx)

Hottest day (TXx) at Mill Creek Summit by year The hottest day of the year at Mill Creek Summit, 1979 to 2026. The record is 31.0 C (87.8 F) in 2000, marked on the chart; the median year is 27.3 C (81.1 F). 242628303219801990200020102020Record: 31.0 C (87.8 F) in 2000
The hottest day of the year at Mill Creek Summit, 1979 to 2026. The record is 31.0 C (87.8 F) in 2000, marked on the chart; the median year is 27.3 C (81.1 F).
Hottest day (TXx) at Mill Creek Summit by year
YearHottest day (TXx)
1979n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
198927.7 C (81.9 F)
199027.0 C (80.6 F)
199126.9 C (80.4 F)
199226.0 C (78.8 F)
199324.7 C (76.5 F)
199427.2 C (81.0 F)
199524.9 C (76.8 F)
199626.2 C (79.2 F)
199725.1 C (77.2 F)
199828.4 C (83.1 F)
199926.5 C (79.7 F)
200031.0 C (87.8 F)
200127.7 C (81.9 F)
200230.1 C (86.2 F)
200329.9 C (85.8 F)
200427.9 C (82.2 F)
200528.4 C (83.1 F)
200629.7 C (85.5 F)
200729.5 C (85.1 F)
200826.7 C (80.1 F)
200926.9 C (80.4 F)
201026.1 C (79.0 F)
201126.1 C (79.0 F)
201227.0 C (80.6 F)
201328.1 C (82.6 F)
201428.5 C (83.3 F)
201528.4 C (83.1 F)
201626.6 C (79.9 F)
201727.3 C (81.1 F)
201828.9 C (84.0 F)
201926.9 C (80.4 F)
202027.3 C (81.1 F)
202127.8 C (82.0 F)
202227.1 C (80.8 F)
202328.1 C (82.6 F)
202428.1 C (82.6 F)
202526.9 C (80.4 F)
202627.2 C (81.0 F)

Coldest night (TNn)

Coldest night (TNn) at Mill Creek Summit by year The coldest night of the year at Mill Creek Summit, 1979 to 2026. The record is -33.9 C (-29.0 F) in 1990, marked on the chart; the median year is -25.6 C (-14.2 F). -35-30-25-2019801990200020102020Record: -33.9 C (-29.0 F) in 1990
The coldest night of the year at Mill Creek Summit, 1979 to 2026. The record is -33.9 C (-29.0 F) in 1990, marked on the chart; the median year is -25.6 C (-14.2 F).
Coldest night (TNn) at Mill Creek Summit by year
YearColdest night (TNn)
1979n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
1989-22.8 C (-9.0 F)
1990-33.9 C (-29.0 F)
1991-25.1 C (-13.2 F)
1992-22.7 C (-8.9 F)
1993-26.6 C (-15.9 F)
1994-23.4 C (-10.1 F)
1995-20.4 C (-4.7 F)
1996-25.8 C (-14.4 F)
1997-30.1 C (-22.2 F)
1998-31.4 C (-24.5 F)
1999-24.7 C (-12.5 F)
2000-21.8 C (-7.2 F)
2001-25.6 C (-14.1 F)
2002-25.0 C (-13.0 F)
2003-24.9 C (-12.8 F)
2004-25.1 C (-13.2 F)
2005-26.8 C (-16.2 F)
2006-26.6 C (-15.9 F)
2007-28.2 C (-18.8 F)
2008-25.4 C (-13.7 F)
2009-28.1 C (-18.6 F)
2010-27.4 C (-17.3 F)
2011-27.5 C (-17.5 F)
2012-23.0 C (-9.4 F)
2013-29.2 C (-20.6 F)
2014-27.5 C (-17.5 F)
2015-24.9 C (-12.8 F)
2016-27.1 C (-16.8 F)
2017-26.6 C (-15.9 F)
2018-25.7 C (-14.3 F)
2019-25.4 C (-13.7 F)
2020-24.1 C (-11.4 F)
2021-25.6 C (-14.1 F)
2022-27.1 C (-16.8 F)
2023-29.7 C (-21.5 F)
2024-24.2 C (-11.6 F)
2025-28.8 C (-19.8 F)
2026-22.5 C (-8.5 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Mill Creek Summit by year The wettest day of the year at Mill Creek Summit, 1979 to 2026. The record is 58.4 mm (2.3 in) in 2026, marked on the chart; the median year is 30.5 mm (1.2 in). 203040506019801990200020102020Record: 58.4 mm (2.3 in) in 2026
The wettest day of the year at Mill Creek Summit, 1979 to 2026. The record is 58.4 mm (2.3 in) in 2026, marked on the chart; the median year is 30.5 mm (1.2 in).
Wettest day (Rx1day) at Mill Creek Summit by year
YearWettest day (Rx1day)
197920.3 mm (0.8 in)
198122.9 mm (0.9 in)
198230.5 mm (1.2 in)
198355.9 mm (2.2 in)
198448.3 mm (1.9 in)
198530.5 mm (1.2 in)
198638.1 mm (1.5 in)
198727.9 mm (1.1 in)
198827.9 mm (1.1 in)
198920.3 mm (0.8 in)
199030.5 mm (1.2 in)
199127.9 mm (1.1 in)
199227.9 mm (1.1 in)
199335.6 mm (1.4 in)
199425.4 mm (1.0 in)
199548.3 mm (1.9 in)
199643.2 mm (1.7 in)
199755.9 mm (2.2 in)
199838.1 mm (1.5 in)
199935.6 mm (1.4 in)
200033.0 mm (1.3 in)
200127.9 mm (1.1 in)
200225.4 mm (1.0 in)
200322.9 mm (0.9 in)
200427.9 mm (1.1 in)
200522.9 mm (0.9 in)
200643.2 mm (1.7 in)
200735.6 mm (1.4 in)
200833.0 mm (1.3 in)
200935.6 mm (1.4 in)
201027.9 mm (1.1 in)
201122.9 mm (0.9 in)
201238.1 mm (1.5 in)
201330.5 mm (1.2 in)
201422.9 mm (0.9 in)
201533.0 mm (1.3 in)
201622.9 mm (0.9 in)
201735.6 mm (1.4 in)
201820.3 mm (0.8 in)
201925.4 mm (1.0 in)
202027.9 mm (1.1 in)
202130.5 mm (1.2 in)
202225.4 mm (1.0 in)
202327.9 mm (1.1 in)
202422.9 mm (0.9 in)
202533.0 mm (1.3 in)
202658.4 mm (2.3 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Mill Creek Summit by year The wettest five days of the year at Mill Creek Summit, 1979 to 2026. The record is 172.7 mm (6.8 in) in 1997, marked on the chart; the median year is 61.0 mm (2.4 in). 05010015020019801990200020102020Record: 172.7 mm (6.8 in) in 1997
The wettest five days of the year at Mill Creek Summit, 1979 to 2026. The record is 172.7 mm (6.8 in) in 1997, marked on the chart; the median year is 61.0 mm (2.4 in).
Wettest five days (Rx5day) at Mill Creek Summit by year
YearWettest five days (Rx5day)
1979n/a
198145.7 mm (1.8 in)
198278.8 mm (3.1 in)
198356.0 mm (2.2 in)
198455.9 mm (2.2 in)
198561.0 mm (2.4 in)
1986137.1 mm (5.4 in)
198755.9 mm (2.2 in)
198843.2 mm (1.7 in)
198940.7 mm (1.6 in)
199068.6 mm (2.7 in)
199186.3 mm (3.4 in)
199248.3 mm (1.9 in)
199391.4 mm (3.6 in)
199443.1 mm (1.7 in)
199573.7 mm (2.9 in)
1996134.6 mm (5.3 in)
1997172.7 mm (6.8 in)
1998106.7 mm (4.2 in)
199989.0 mm (3.5 in)
200078.7 mm (3.1 in)
200153.3 mm (2.1 in)
200250.8 mm (2.0 in)
200366.1 mm (2.6 in)
200453.4 mm (2.1 in)
200561.0 mm (2.4 in)
200661.0 mm (2.4 in)
200755.9 mm (2.2 in)
200853.4 mm (2.1 in)
200966.1 mm (2.6 in)
201045.6 mm (1.8 in)
201150.8 mm (2.0 in)
201291.4 mm (3.6 in)
201373.7 mm (2.9 in)
201458.5 mm (2.3 in)
201555.9 mm (2.2 in)
201653.4 mm (2.1 in)
201791.5 mm (3.6 in)
201848.3 mm (1.9 in)
201983.8 mm (3.3 in)
202043.3 mm (1.7 in)
202163.5 mm (2.5 in)
202266.1 mm (2.6 in)
202350.8 mm (2.0 in)
202455.8 mm (2.2 in)
202576.2 mm (3.0 in)
202668.5 mm (2.7 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Mill Creek Summit by year The longest dry spell of the year at Mill Creek Summit, 1979 to 2026. The record is 91 days in 1988, marked on the chart; the median year is 25 days. 025507510019801990200020102020Record: 91 days in 1988
The longest dry spell of the year at Mill Creek Summit, 1979 to 2026. The record is 91 days in 1988, marked on the chart; the median year is 25 days.
Longest dry spell (CDD) at Mill Creek Summit by year
YearLongest dry spell (CDD)
19791 day
19813 days
198214 days
198325 days
198437 days
198554 days
198647 days
198779 days
198891 days
198946 days
199038 days
199126 days
199221 days
199323 days
199443 days
199520 days
199623 days
199712 days
199817 days
199953 days
200047 days
200131 days
200236 days
200325 days
200415 days
200523 days
200614 days
200727 days
200838 days
200919 days
201014 days
201123 days
201232 days
201311 days
201441 days
201518 days
201641 days
201734 days
201819 days
201925 days
202031 days
202128 days
202228 days
202316 days
202417 days
202525 days
202628 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

36 years with a frost

Across 36 years with a frost, the median last spring frost at Mill Creek Summit falls on 26 June and the median first autumn frost on 6 July, which leaves a median of 14 days between them.

Fitted over all years, the growing season changes by +8.4 days per decade at this station.

Frost dates and growing season at Mill Creek Summit
MeasureMedian, all yearsEarliest periodRecent period (1996 to 2025)Recent against earliestFitted trend
Last spring frost26 Junen/a26 Junen/a-0.3 days per decade
First autumn frost6 Julyn/a18 Julyn/a+8.1 days per decade
Growing days14 daysn/a26 daysn/a+8.4 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

42 years, 1983 to 2025

A day with at least 29.6 mm (1.2 in) of rain is expected about once in 2 years. A day with at least 62.3 mm (2.5 in) of rain is expected about once in 100 years.

Rainfall return levels at Mill Creek Summit: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years29.6 mm (1.2 in)
5 years37.0 mm (1.5 in)
10 years42.4 mm (1.7 in)
25 years49.8 mm (2.0 in)
50 years55.8 mm (2.2 in)Longer than the 42 years of record
100 years62.3 mm (2.5 in)Longer than the 42 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, 42 years of values from 1983 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: 55.9 mm (2.2 in) in 1983; 55.9 mm (2.2 in) in 1997; 48.3 mm (1.9 in) in 1995.

Download the Data

  • Data for Mill Creek Summit standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Mill Creek Summit 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-17).