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Built 2026-10-19 (19 October 2026)

Mammoth-Cottonwood Weather Records (USS0011K03S)

Record envelope, standing records and threshold days for Mammoth-Cottonwood (USS0011K03S), Utah, United States, with 49 years of record.

Key Facts for Mammoth-Cottonwood

  • Mammoth-Cottonwood (USS0011K03S) is a weather station in Utah, United States at 39.68 latitude and -111.32 longitude, 2,660 m (8,727 ft) above sea level.
  • The station reports from 1978 to 2026, 49 years of record.
  • 1,464 records set at Mammoth-Cottonwood still stand.
  • Records are tracked for prcp: an element needs 30 years of data to be eligible.
  • Mammoth-Cottonwood tied a daily record precipitation of 17.8 mm (0.7 in) on 12 October 2026 (provisional).

Provisional Records

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

About the Station

  • Location: Utah, United States, 39.68 latitude, -111.32 longitude.
  • Elevation: 2,660 m (8,727 ft).
  • Period of record: 1978 to 2026, 49 years.
  • Eligible elements: prcp.

Daily Record Envelope and 2026

30 days at or beyond a record
Daily record high and record low at Mammoth-Cottonwood, with 2026 drawn through them The band shows the record high and record low for each calendar day at Mammoth-Cottonwood. The lines show the 2026 daily maximum and minimum. 30 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 Mammoth-Cottonwood. The lines show the 2026 daily maximum and minimum. 30 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Mammoth-Cottonwood, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan15.2 C (59.4 F)-29.0 C (-20.2 F)9.5 C (49.1 F)-18.1 C (-0.6 F)
Feb16.3 C (61.3 F)-31.7 C (-25.1 F)12.6 C (54.7 F)-20.2 C (-4.4 F)
Mar19.8 C (67.6 F)-23.1 C (-9.6 F)19.8 C (67.6 F)-16.8 C (1.8 F)
Apr22.8 C (73.0 F)-22.3 C (-8.1 F)16.2 C (61.2 F)-11.8 C (10.8 F)
May24.0 C (75.2 F)-13.4 C (7.9 F)22.3 C (72.1 F)-6.1 C (21.0 F)
Jun28.7 C (83.7 F)-6.9 C (19.6 F)24.2 C (75.6 F)-2.7 C (27.1 F)
Jul29.9 C (85.8 F)1.0 C (33.8 F)29.9 C (85.8 F)1.5 C (34.7 F)
Aug29.7 C (85.5 F)-2.1 C (28.2 F)29.2 C (84.6 F)3.9 C (39.0 F)
Sep29.3 C (84.7 F)-12.0 C (10.4 F)22.3 C (72.1 F)0.3 C (32.5 F)
Oct24.5 C (76.1 F)-24.1 C (-11.4 F)21.2 C (70.2 F)-3.2 C (26.2 F)
Nov17.1 C (62.8 F)-25.7 C (-14.3 F)n/an/a
Dec15.0 C (59.0 F)-27.1 C (-16.8 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Mammoth-Cottonwood by the year they were set 1,464 records at Mammoth-Cottonwood still stand. 2020 holds the most, with 89. 02550751002005: 322006: 672007: 682008: 752009: 622010: 732011: 502012: 662013: 792014: 632015: 822016: 702017: 642018: 612019: 522020: 892021: 692022: 892023: 602024: 612025: 732026: 5920052008201120142017202020232026
1,464 records at Mammoth-Cottonwood still stand. 2020 holds the most, with 89.
Standing records at Mammoth-Cottonwood by the year they were set
Year setStanding records
200532
200667
200768
200875
200962
201073
201150
201266
201379
201463
201582
201670
201764
201861
201952
202089
202169
202289
202360
202461
202573
202659

Wettest Day of Each Month

Jan: 76.2 mm (3.0 in)
Record daily precipitation for each month at Mammoth-Cottonwood The wettest day on record for each calendar month at Mammoth-Cottonwood. The most was 76.2 mm (3.0 in) on 4 January 1982. 020406080 Jan: 76.2 mm (3.0 in), 4 January 1982 Jan Feb: 43.2 mm (1.7 in), 20 February 1996 Feb Mar: 38.1 mm (1.5 in), 10 March 2023 Mar Apr: 25.4 mm (1.0 in), 19 April 1985 Apr May: 35.6 mm (1.4 in), 24 May 2000 May Jun: 38.1 mm (1.5 in), 6 June 1984 Jun Jul: 30.5 mm (1.2 in), 8 July 2004 Jul Aug: 38.1 mm (1.5 in), 18 August 2021 Aug Sep: 43.2 mm (1.7 in), 26 September 1982 Sep Oct: 35.6 mm (1.4 in), 20 October 2004 Oct Nov: 38.1 mm (1.5 in), 22 November 1996 Nov Dec: 55.9 mm (2.2 in), 29 December 2010 Dec
The wettest day on record for each calendar month at Mammoth-Cottonwood. The most was 76.2 mm (3.0 in) on 4 January 1982.
Record daily precipitation for each month at Mammoth-Cottonwood
MonthRecord daily precipitation (mm)Date
Jan76.2 mm (3.0 in)4 January 1982
Feb43.2 mm (1.7 in)20 February 1996
Mar38.1 mm (1.5 in)10 March 2023
Apr25.4 mm (1.0 in)19 April 1985
May35.6 mm (1.4 in)24 May 2000
Jun38.1 mm (1.5 in)6 June 1984
Jul30.5 mm (1.2 in)8 July 2004
Aug38.1 mm (1.5 in)18 August 2021
Sep43.2 mm (1.7 in)26 September 1982
Oct35.6 mm (1.4 in)20 October 2004
Nov38.1 mm (1.5 in)22 November 1996
Dec55.9 mm (2.2 in)29 December 2010

Period of Record Coverage

2005 to 2026
Days with data per year at Mammoth-Cottonwood 22 years of record at Mammoth-Cottonwood, 2005 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 2005, 2026. 2005: 180 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: 362 of 365 days2016: 366 of 366 days2017: 365 of 365 days2018: 365 of 365 days2019: 364 of 365 days2020: 366 of 366 days2021: 363 of 365 days2022: 365 of 365 days2023: 365 of 365 days2024: 364 of 366 days2025: 365 of 365 days2026: 287 of 365 days20052010201520202025
22 years of record at Mammoth-Cottonwood, 2005 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 2005, 2026.
Days with data per year at Mammoth-Cottonwood
YearDays with dataShare of yearComplete
200518049%No
2006365100%Yes
2007365100%Yes
2008366100%Yes
2009365100%Yes
2010365100%Yes
2011365100%Yes
2012366100%Yes
2013365100%Yes
2014365100%Yes
201536299%Yes
2016366100%Yes
2017365100%Yes
2018365100%Yes
2019364100%Yes
2020366100%Yes
202136399%Yes
2022365100%Yes
2023365100%Yes
202436499%Yes
2025365100%Yes
202628779%No

Latest Records

20
Latest records at Mammoth-Cottonwood
DateStationRecordValueBeat old record byOld record stoodSignificance
12 October 2026Mammoth-Cottonwood, USdaily rain (Tie, Provisional)17.8 mm (0.7 in)tie37 years3 of 100 (Routine)
11 October 2026Mammoth-Cottonwood, USdaily rain (Provisional)30.5 mm (1.2 in)12.7 mm (0.5 in)32 years34 of 100 (Routine)
29 August 2026Mammoth-Cottonwood, USdaily rain (Provisional)22.9 mm (0.9 in)7.7 mm (0.30 in)25 years20 of 100 (Routine)
22 August 2026Mammoth-Cottonwood, USdaily rain (Provisional)20.3 mm (0.8 in)7.6 mm (0.30 in)33 years20 of 100 (Routine)
14 August 2026Mammoth-Cottonwood, USdaily rain (Tie)5.1 mm (0.20 in)tie35 years3 of 100 (Routine)
27 June 2026Mammoth-Cottonwood, USdaily rain (Tie)2.5 mm (0.10 in)tie29 years3 of 100 (Routine)
1 April 2026Mammoth-Cottonwood, USdaily rain (Tie)22.9 mm (0.9 in)tie47 years4 of 100 (Routine)
26 August 2025Mammoth-Cottonwood, USdaily rain15.2 mm (0.6 in)5.0 mm (0.20 in)36 years20 of 100 (Routine)
22 June 2025Mammoth-Cottonwood, USdaily rain (Tie)2.5 mm (0.10 in)tie46 years4 of 100 (Routine)
14 May 2025Mammoth-Cottonwood, USdaily rain (Tie)7.6 mm (0.30 in)tie10 years1 of 100 (Routine)
17 April 2025Mammoth-Cottonwood, USdaily rain (Tie)15.2 mm (0.6 in)tie30 years3 of 100 (Routine)
18 March 2025Mammoth-Cottonwood, USdaily rain17.8 mm (0.7 in)5.1 mm (0.20 in)44 years20 of 100 (Routine)
13 March 2025Mammoth-Cottonwood, USdaily rain15.2 mm (0.6 in)2.5 mm (0.10 in)15 years13 of 100 (Routine)
6 March 2025Mammoth-Cottonwood, USdaily rain30.5 mm (1.2 in)10.2 mm (0.4 in)6 years25 of 100 (Routine)
14 February 2025Mammoth-Cottonwood, USdaily rain (Tie)20.3 mm (0.8 in)tie45 years4 of 100 (Routine)
13 February 2025Mammoth-Cottonwood, USdaily rain22.9 mm (0.9 in)5.1 mm (0.20 in)38 years20 of 100 (Routine)
27 December 2024Mammoth-Cottonwood, USdaily rain20.3 mm (0.8 in)5.1 mm (0.20 in)41 years20 of 100 (Routine)
26 November 2024Mammoth-Cottonwood, USdaily rain (Tie)30.5 mm (1.2 in)tie35 years3 of 100 (Routine)
12 November 2024Mammoth-Cottonwood, USdaily rain (Tie)10.2 mm (0.4 in)tie39 years3 of 100 (Routine)
29 October 2024Mammoth-Cottonwood, USdaily rain (Tie)12.7 mm (0.5 in)tie32 years3 of 100 (Routine)

Climate Trend

20 complete years, 2006 to 2025
Annual mean temperature at Mammoth-Cottonwood as warming stripes, 2006 to 2025 One stripe for each of 20 complete years at Mammoth-Cottonwood, 2006 to 2025. Blue stripes are years cooler than the station's own mean of 3.6 C (38.5 F); red stripes are warmer. The coolest year was 2008, at 2.4 C (36.4 F), and the warmest was 2025, at 4.7 C (40.4 F). The strongest colour marks a difference of 1.3 C (2.3 F). 2006: 3.2 C, -0.4 C from the station mean2007: 3.8 C, +0.2 C from the station mean2008: 2.4 C, -1.2 C from the station mean2009: 2.9 C, -0.8 C from the station mean2010: 3.0 C, -0.7 C from the station mean2011: 2.6 C, -1.1 C from the station mean2012: 4.3 C, +0.7 C from the station mean2013: 3.0 C, -0.7 C from the station mean2014: 3.8 C, +0.2 C from the station mean2015: 4.5 C, +0.9 C from the station mean2016: 4.2 C, +0.6 C from the station mean2017: 4.4 C, +0.8 C from the station mean2018: 4.0 C, +0.4 C from the station mean2019: 2.7 C, -0.9 C from the station mean2020: 4.1 C, +0.4 C from the station mean2021: 4.2 C, +0.5 C from the station mean2022: 3.5 C, -0.2 C from the station mean2023: 3.1 C, -0.5 C from the station mean2024: 4.3 C, +0.7 C from the station mean2025: 4.7 C, +1.1 C from the station mean2006200820102012201420162018202020222024
One stripe for each of 20 complete years at Mammoth-Cottonwood, 2006 to 2025. Blue stripes are years cooler than the station's own mean of 3.6 C (38.5 F); red stripes are warmer. The coolest year was 2008, at 2.4 C (36.4 F), and the warmest was 2025, at 4.7 C (40.4 F). The strongest colour marks a difference of 1.3 C (2.3 F).
Annual mean temperature at Mammoth-Cottonwood as warming stripes, 2006 to 2025
YearAnnual mean temperatureDifference from the station mean
20063.2 C-0.41 C
20073.8 C+0.19 C
20082.4 C-1.21 C
20092.9 C-0.77 C
20103.0 C-0.66 C
20112.6 C-1.07 C
20124.3 C+0.69 C
20133.0 C-0.67 C
20143.8 C+0.20 C
20154.5 C+0.87 C
20164.2 C+0.58 C
20174.4 C+0.75 C
20184.0 C+0.38 C
20192.7 C-0.93 C
20204.1 C+0.43 C
20214.2 C+0.53 C
20223.5 C-0.17 C
20233.1 C-0.50 C
20244.3 C+0.69 C
20254.7 C+1.06 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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

1978 to 2026
Yearly extremes at Mammoth-Cottonwood: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)29.9 C (85.8 F)202628.5 C (83.2 F)22
Coldest night (TNn)-31.7 C (-25.1 F)2011-25.1 C (-13.2 F)22
Wettest day (Rx1day)76.2 mm (3.0 in)198230.5 mm (1.2 in)49
Wettest five days (Rx5day)215.8 mm (8.5 in)198260.9 mm (2.4 in)48
Longest dry spell (CDD)49 days198626 days49

Hottest day (TXx)

Hottest day (TXx) at Mammoth-Cottonwood by year The hottest day of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 29.9 C (85.8 F) in 2026, marked on the chart; the median year is 28.5 C (83.2 F). 262728293019801990200020102020Record: 29.9 C (85.8 F) in 2026
The hottest day of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 29.9 C (85.8 F) in 2026, marked on the chart; the median year is 28.5 C (83.2 F).
Hottest day (TXx) at Mammoth-Cottonwood by year
YearHottest day (TXx)
1978n/a
1979n/a
1980n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
1989n/a
1990n/a
1991n/a
1992n/a
1993n/a
1994n/a
1995n/a
1996n/a
1997n/a
1998n/a
1999n/a
2000n/a
2001n/a
2002n/a
2003n/a
2004n/a
200528.8 C (83.8 F)
200628.7 C (83.7 F)
200728.3 C (82.9 F)
200826.8 C (80.2 F)
200927.6 C (81.7 F)
201027.9 C (82.2 F)
201126.1 C (79.0 F)
201227.2 C (81.0 F)
201328.6 C (83.5 F)
201427.6 C (81.7 F)
201528.7 C (83.7 F)
201628.6 C (83.5 F)
201728.1 C (82.6 F)
201827.7 C (81.9 F)
201927.8 C (82.0 F)
202029.7 C (85.5 F)
202128.7 C (83.7 F)
202229.3 C (84.7 F)
202328.7 C (83.7 F)
202429.0 C (84.2 F)
202527.8 C (82.0 F)
202629.9 C (85.8 F)

Coldest night (TNn)

Coldest night (TNn) at Mammoth-Cottonwood by year The coldest night of the year at Mammoth-Cottonwood, 1978 to 2026. The record is -31.7 C (-25.1 F) in 2011, marked on the chart; the median year is -25.1 C (-13.2 F). -35-30-25-2019801990200020102020Record: -31.7 C (-25.1 F) in 2011
The coldest night of the year at Mammoth-Cottonwood, 1978 to 2026. The record is -31.7 C (-25.1 F) in 2011, marked on the chart; the median year is -25.1 C (-13.2 F).
Coldest night (TNn) at Mammoth-Cottonwood by year
YearColdest night (TNn)
1978n/a
1979n/a
1980n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
1989n/a
1990n/a
1991n/a
1992n/a
1993n/a
1994n/a
1995n/a
1996n/a
1997n/a
1998n/a
1999n/a
2000n/a
2001n/a
2002n/a
2003n/a
2004n/a
2005-26.8 C (-16.2 F)
2006-25.2 C (-13.4 F)
2007-27.4 C (-17.3 F)
2008-25.4 C (-13.7 F)
2009-27.5 C (-17.5 F)
2010-25.7 C (-14.3 F)
2011-31.7 C (-25.1 F)
2012-23.3 C (-9.9 F)
2013-29.0 C (-20.2 F)
2014-22.4 C (-8.3 F)
2015-22.3 C (-8.1 F)
2016-24.1 C (-11.4 F)
2017-25.6 C (-14.1 F)
2018-25.0 C (-13.0 F)
2019-25.5 C (-13.9 F)
2020-22.8 C (-9.0 F)
2021-21.5 C (-6.7 F)
2022-22.9 C (-9.2 F)
2023-27.1 C (-16.8 F)
2024-20.5 C (-4.9 F)
2025-22.7 C (-8.9 F)
2026-20.2 C (-4.4 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Mammoth-Cottonwood by year The wettest day of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 76.2 mm (3.0 in) in 1982, marked on the chart; the median year is 30.5 mm (1.2 in). 02040608019801990200020102020Record: 76.2 mm (3.0 in) in 1982
The wettest day of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 76.2 mm (3.0 in) in 1982, marked on the chart; the median year is 30.5 mm (1.2 in).
Wettest day (Rx1day) at Mammoth-Cottonwood by year
YearWettest day (Rx1day)
197830.5 mm (1.2 in)
197950.8 mm (2.0 in)
198038.1 mm (1.5 in)
198133.0 mm (1.3 in)
198276.2 mm (3.0 in)
198335.6 mm (1.4 in)
198438.1 mm (1.5 in)
198527.9 mm (1.1 in)
198627.9 mm (1.1 in)
198733.0 mm (1.3 in)
198820.3 mm (0.8 in)
198930.5 mm (1.2 in)
199033.0 mm (1.3 in)
199127.9 mm (1.1 in)
199227.9 mm (1.1 in)
199330.5 mm (1.2 in)
199443.2 mm (1.7 in)
199522.9 mm (0.9 in)
199643.2 mm (1.7 in)
199738.1 mm (1.5 in)
199817.8 mm (0.7 in)
199927.9 mm (1.1 in)
200035.6 mm (1.4 in)
200127.9 mm (1.1 in)
200222.9 mm (0.9 in)
200317.8 mm (0.7 in)
200435.6 mm (1.4 in)
200527.9 mm (1.1 in)
200625.4 mm (1.0 in)
200730.5 mm (1.2 in)
200825.4 mm (1.0 in)
200930.5 mm (1.2 in)
201055.9 mm (2.2 in)
201120.3 mm (0.8 in)
201233.0 mm (1.3 in)
201320.3 mm (0.8 in)
201440.6 mm (1.6 in)
201533.0 mm (1.3 in)
201643.2 mm (1.7 in)
201733.0 mm (1.3 in)
201825.4 mm (1.0 in)
201922.9 mm (0.9 in)
202027.9 mm (1.1 in)
202138.1 mm (1.5 in)
202248.3 mm (1.9 in)
202338.1 mm (1.5 in)
202430.5 mm (1.2 in)
202530.5 mm (1.2 in)
202630.5 mm (1.2 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Mammoth-Cottonwood by year The wettest five days of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 215.8 mm (8.5 in) in 1982, marked on the chart; the median year is 60.9 mm (2.4 in). 05010015020025019801990200020102020Record: 215.8 mm (8.5 in) in 1982
The wettest five days of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 215.8 mm (8.5 in) in 1982, marked on the chart; the median year is 60.9 mm (2.4 in).
Wettest five days (Rx5day) at Mammoth-Cottonwood by year
YearWettest five days (Rx5day)
1978n/a
197950.7 mm (2.0 in)
1980109.2 mm (4.3 in)
198168.7 mm (2.7 in)
1982215.8 mm (8.5 in)
198355.8 mm (2.2 in)
198494.0 mm (3.7 in)
198573.7 mm (2.9 in)
198663.5 mm (2.5 in)
198740.7 mm (1.6 in)
198843.2 mm (1.7 in)
198955.9 mm (2.2 in)
199060.9 mm (2.4 in)
199150.8 mm (2.0 in)
199276.2 mm (3.0 in)
199363.5 mm (2.5 in)
199466.0 mm (2.6 in)
199553.4 mm (2.1 in)
199671.0 mm (2.8 in)
199758.4 mm (2.3 in)
199843.2 mm (1.7 in)
199948.3 mm (1.9 in)
200048.3 mm (1.9 in)
200153.3 mm (2.1 in)
200253.4 mm (2.1 in)
200338.0 mm (1.5 in)
200486.4 mm (3.4 in)
200563.4 mm (2.5 in)
200653.4 mm (2.1 in)
200745.7 mm (1.8 in)
200848.3 mm (1.9 in)
200981.2 mm (3.2 in)
2010137.2 mm (5.4 in)
201160.9 mm (2.4 in)
201248.3 mm (1.9 in)
201330.4 mm (1.2 in)
201476.1 mm (3.0 in)
201555.8 mm (2.2 in)
201691.3 mm (3.6 in)
2017101.5 mm (4.0 in)
201860.9 mm (2.4 in)
201955.9 mm (2.2 in)
202063.4 mm (2.5 in)
202178.7 mm (3.1 in)
202293.9 mm (3.7 in)
2023101.6 mm (4.0 in)
202461.0 mm (2.4 in)
202550.8 mm (2.0 in)
202671.2 mm (2.8 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Mammoth-Cottonwood by year The longest dry spell of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 49 days in 1986, marked on the chart; the median year is 26 days. 020406019801990200020102020Record: 49 days in 1986
The longest dry spell of the year at Mammoth-Cottonwood, 1978 to 2026. The record is 49 days in 1986, marked on the chart; the median year is 26 days.
Longest dry spell (CDD) at Mammoth-Cottonwood by year
YearLongest dry spell (CDD)
19782 days
197922 days
198036 days
198118 days
198220 days
198316 days
198414 days
198533 days
198649 days
198732 days
198821 days
198923 days
199021 days
199117 days
199218 days
199331 days
199431 days
199517 days
199621 days
199733 days
199820 days
199918 days
200023 days
200120 days
200241 days
200331 days
200420 days
200524 days
200632 days
200735 days
200834 days
200931 days
201023 days
201119 days
201239 days
201336 days
201423 days
201526 days
201634 days
201736 days
201830 days
201931 days
202033 days
202131 days
202238 days
202333 days
202416 days
202534 days
202624 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

20 years with a frost

Across 20 years with a frost, the median last spring frost at Mammoth-Cottonwood falls on 18 June and the median first autumn frost on 16 September, which leaves a median of 92 days between them.

Frost dates and growing season at Mammoth-Cottonwood
MeasureMedian, all yearsEarliest periodRecent period (2006 to 2025)Recent against earliestFitted trend
Last spring frost18 Junen/a18 Junen/an/a
First autumn frost16 Septembern/a16 Septembern/an/a
Growing days92 daysn/a92 daysn/an/a

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

46 years, 1980 to 2025

A day with at least 30.5 mm (1.2 in) of rain is expected about once in 2 years. A day with at least 65.8 mm (2.6 in) of rain is expected about once in 100 years.

Rainfall return levels at Mammoth-Cottonwood: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years30.5 mm (1.2 in)
5 years39.1 mm (1.5 in)
10 years45.1 mm (1.8 in)
25 years53.1 mm (2.1 in)
50 years59.3 mm (2.3 in)Longer than the 46 years of record
100 years65.8 mm (2.6 in)Longer than the 46 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, 46 years of values from 1980 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: 76.2 mm (3.0 in) in 1982; 55.9 mm (2.2 in) in 2010; 48.3 mm (1.9 in) in 2022.

Download the Data

  • Data for Mammoth-Cottonwood standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Mammoth-Cottonwood 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).