Built 2026-10-15 (15 October 2026)

Porcupine Weather Records (USS0010C03S)

Record envelope, standing records and threshold days for Porcupine (USS0010C03S), Montana, United States, with 49 years of record.

Key Facts for Porcupine

  • Porcupine (USS0010C03S) is a weather station in Montana, United States at 46.11 latitude and -110.47 longitude, 1,981 m (6,500 ft) above sea level.
  • The station reports from 1978 to 2026, 49 years of record.
  • 1,464 records set at Porcupine still stand.
  • Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
  • Porcupine set a daily record precipitation of 12.7 mm (0.5 in) 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: Montana, United States, 46.11 latitude, -110.47 longitude.
  • Elevation: 1,981 m (6,500 ft).
  • Period of record: 1978 to 2026, 49 years.
  • Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

16 days at or beyond a record
Daily record high and record low at Porcupine, with 2026 drawn through them The band shows the record high and record low for each calendar day at Porcupine. The lines show the 2026 daily maximum and minimum. 16 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 Porcupine. The lines show the 2026 daily maximum and minimum. 16 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Porcupine, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan12.6 C (54.7 F)-34.3 C (-29.7 F)8.3 C (46.9 F)-19.1 C (-2.4 F)
Feb14.0 C (57.2 F)-33.4 C (-28.1 F)12.7 C (54.9 F)-16.6 C (2.1 F)
Mar19.5 C (67.1 F)-28.7 C (-19.7 F)19.5 C (67.1 F)-14.2 C (6.4 F)
Apr23.9 C (75.0 F)-19.4 C (-2.9 F)22.2 C (72.0 F)-8.1 C (17.4 F)
May26.8 C (80.2 F)-9.8 C (14.4 F)25.5 C (77.9 F)-4.6 C (23.7 F)
Jun32.7 C (90.9 F)-5.0 C (23.0 F)24.0 C (75.2 F)-0.8 C (30.6 F)
Jul34.1 C (93.4 F)-1.3 C (29.7 F)33.8 C (92.8 F)6.5 C (43.7 F)
Aug33.7 C (92.7 F)-4.4 C (24.1 F)32.8 C (91.0 F)3.0 C (37.4 F)
Sep32.3 C (90.1 F)-9.8 C (14.4 F)24.9 C (76.8 F)-0.2 C (31.6 F)
Oct26.9 C (80.4 F)-21.9 C (-7.4 F)23.0 C (73.4 F)-0.7 C (30.7 F)
Nov19.5 C (67.1 F)-26.7 C (-16.1 F)n/an/a
Dec12.4 C (54.3 F)-36.3 C (-33.3 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Porcupine by the year they were set 1,464 records at Porcupine still stand. 1996 holds the most, with 85. 02550751001990: 271991: 331992: 411993: 761994: 411995: 431996: 851997: 451998: 261999: 342000: 302001: 222002: 402003: 372004: 272005: 602006: 322007: 382008: 402009: 462010: 322011: 242012: 392013: 302014: 402015: 372016: 402017: 422018: 232019: 312020: 432021: 552022: 482023: 282024: 462025: 412026: 421990199419982002200620102014201820222026
1,464 records at Porcupine still stand. 1996 holds the most, with 85.
Standing records at Porcupine by the year they were set
Year setStanding records
199027
199133
199241
199376
199441
199543
199685
199745
199826
199934
200030
200122
200240
200337
200427
200560
200632
200738
200840
200946
201032
201124
201239
201330
201440
201537
201640
201742
201823
201931
202043
202155
202248
202328
202446
202541
202642

All-Time Record Progression

2 new records
When Porcupine set new all-time records 2 all-time records were set at Porcupine between 22 December 2022 and 24 July 2024. Each dot is a new record. Record low minimum temperatureRecord high minimum temperature22 December 2022: Record low minimum temperature -36.3 C (-33.3 F)24 July 2024: Record high minimum temperature 17.1 C (62.8 F)2025
2 all-time records were set at Porcupine between 22 December 2022 and 24 July 2024. Each dot is a new record.
When Porcupine set new all-time records
DateKindDetail
2022-12-22Record low minimum temperatureRecord low minimum temperature -36.3 C (-33.3 F)
2024-07-24Record high minimum temperatureRecord high minimum temperature 17.1 C (62.8 F)

Wettest Day of Each Month

Jun: 111.8 mm (4.4 in)
Record daily precipitation for each month at Porcupine The wettest day on record for each calendar month at Porcupine. The most was 111.8 mm (4.4 in) on 18 June 1979. 050100150 Jan: 22.9 mm (0.9 in), 19 January 2008 Jan Feb: 22.9 mm (0.9 in), 21 February 1979 Feb Mar: 38.1 mm (1.5 in), 24 March 1995 Mar Apr: 43.2 mm (1.7 in), 22 April 1992 Apr May: 48.3 mm (1.9 in), 17 May 2017 May Jun: 111.8 mm (4.4 in), 18 June 1979 Jun Jul: 58.4 mm (2.3 in), 3 July 1993 Jul Aug: 45.7 mm (1.8 in), 2 August 1985 Aug Sep: 58.4 mm (2.3 in), 18 September 2024 Sep Oct: 45.7 mm (1.8 in), 4 October 1992 Oct Nov: 30.5 mm (1.2 in), 26 November 2005 Nov Dec: 22.9 mm (0.9 in), 3 December 1998 Dec
The wettest day on record for each calendar month at Porcupine. The most was 111.8 mm (4.4 in) on 18 June 1979.
Record daily precipitation for each month at Porcupine
MonthRecord daily precipitation (mm)Date
Jan22.9 mm (0.9 in)19 January 2008
Feb22.9 mm (0.9 in)21 February 1979
Mar38.1 mm (1.5 in)24 March 1995
Apr43.2 mm (1.7 in)22 April 1992
May48.3 mm (1.9 in)17 May 2017
Jun111.8 mm (4.4 in)18 June 1979
Jul58.4 mm (2.3 in)3 July 1993
Aug45.7 mm (1.8 in)2 August 1985
Sep58.4 mm (2.3 in)18 September 2024
Oct45.7 mm (1.8 in)4 October 1992
Nov30.5 mm (1.2 in)26 November 2005
Dec22.9 mm (0.9 in)3 December 1998

Period of Record Coverage

1990 to 2026
Days with data per year at Porcupine 37 years of record at Porcupine, 1990 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1990, 2026. 1990: 146 of 365 days1991: 358 of 365 days1992: 334 of 366 days1993: 335 of 365 days1994: 350 of 365 days1995: 365 of 365 days1996: 365 of 366 days1997: 362 of 365 days1998: 365 of 365 days1999: 364 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: 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: 364 of 365 days2020: 366 of 366 days2021: 364 of 365 days2022: 365 of 365 days2023: 365 of 365 days2024: 366 of 366 days2025: 365 of 365 days2026: 283 of 365 days19901995200020052010201520202025
37 years of record at Porcupine, 1990 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1990, 2026.
Days with data per year at Porcupine
YearDays with dataShare of yearComplete
199014640%No
199135898%Yes
199233491%Yes
199333592%Yes
199435096%Yes
1995365100%Yes
1996365100%Yes
199736299%Yes
1998365100%Yes
1999364100%Yes
2000366100%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
2019364100%Yes
2020366100%Yes
2021364100%Yes
2022365100%Yes
2023365100%Yes
2024366100%Yes
2025365100%Yes
202628378%No

Latest Records

20
Latest records at Porcupine
DateStationRecordValueBeat old record byOld record stoodSignificance
10 October 2026Porcupine, USdaily rain (Provisional)12.7 mm (0.5 in)7.6 mm (0.30 in)25 years20 of 100 (Routine)
9 October 2026Porcupine, USdaily high min (Provisional)11.1 C (52.0 F)1.0 C (1.8 F)1 year4 of 100 (Routine)
9 October 2026Porcupine, USdaily high max (Provisional)22.8 C (73.0 F)0.6 C (1.1 F)1 year3 of 100 (Routine)
5 October 2026Porcupine, USdaily high min (Provisional)12.7 C (54.9 F)1.5 C (2.7 F)4 years6 of 100 (Routine)
19 September 2026Porcupine, USdaily rain (Provisional)12.7 mm (0.5 in)5.1 mm (0.20 in)45 years20 of 100 (Routine)
14 September 2026Porcupine, USdaily rain (Tie, Provisional)17.8 mm (0.7 in)tie40 years4 of 100 (Routine)
7 September 2026Porcupine, USdaily rain (Provisional)12.7 mm (0.5 in)2.5 mm (0.10 in)13 years11 of 100 (Routine)
29 August 2026Porcupine, USdaily rain (Tie, Provisional)7.6 mm (0.30 in)tie44 years4 of 100 (Routine)
21 August 2026Porcupine, USdaily high min (Provisional)15.9 C (60.6 F)1.1 C (2.0 F)16 years10 of 100 (Routine)
8 August 2026Porcupine, USdaily high min14.4 C (57.9 F)0.1 C (0.2 F)13 years7 of 100 (Routine)
1 August 2026Porcupine, USdaily high max32.8 C (91.0 F)1.6 C (2.9 F)4 years7 of 100 (Routine)
1 August 2026Porcupine, USdaily high min16.2 C (61.2 F)0.2 C (0.4 F)4 years4 of 100 (Routine)
26 July 2026Porcupine, USdaily high min16.1 C (61.0 F)0.3 C (0.5 F)4 years4 of 100 (Routine)
25 July 2026Porcupine, USdaily high min15.9 C (60.6 F)1.4 C (2.5 F)4 years8 of 100 (Routine)
25 July 2026Porcupine, USdaily high max31.0 C (87.8 F)0.4 C (0.7 F)15 years7 of 100 (Routine)
14 July 2026Porcupine, USdaily rain7.6 mm (0.30 in)2.5 mm (0.10 in)47 years20 of 100 (Routine)
12 July 2026Porcupine, USdaily high min17.0 C (62.6 F)1.1 C (2.0 F)24 years13 of 100 (Routine)
11 July 2026Porcupine, USdaily high max30.9 C (87.6 F)0.1 C (0.2 F)24 years10 of 100 (Routine)
29 June 2026Porcupine, USdaily low max6.4 C (43.5 F)1.7 C (3.1 F)5 years6 of 100 (Routine)
29 June 2026Porcupine, USdaily rain (Tie)27.9 mm (1.1 in)tie8 years1 of 100 (Routine)

Climate Trend

34 complete years, 1991 to 2025
Annual mean temperature at Porcupine as warming stripes, 1991 to 2025 One stripe for each of 34 complete years at Porcupine, 1991 to 2025. Blue stripes are years cooler than the station's own mean of 5.0 C (41.0 F); red stripes are warmer. The coolest year was 1993, at 1.8 C (35.2 F), and the warmest was 2012, at 6.5 C (43.7 F). The strongest colour marks a difference of 3.3 C (5.9 F). 1991: 4.5 C, -0.5 C from the station mean1993: 1.8 C, -3.2 C from the station mean1994: 3.8 C, -1.2 C from the station mean1995: 3.1 C, -1.9 C from the station mean1996: 2.4 C, -2.6 C from the station mean1997: 2.8 C, -2.2 C from the station mean1998: 4.8 C, -0.3 C from the station mean1999: 5.7 C, +0.6 C from the station mean2000: 5.1 C, +0.1 C from the station mean2001: 5.9 C, +0.9 C from the station mean2002: 4.2 C, -0.8 C from the station mean2003: 5.7 C, +0.7 C from the station mean2004: 4.9 C, -0.1 C from the station mean2005: 4.6 C, -0.4 C from the station mean2006: 6.2 C, +1.1 C from the station mean2007: 6.1 C, +1.0 C from the station mean2008: 4.7 C, -0.3 C from the station mean2009: 4.7 C, -0.3 C from the station mean2010: 5.1 C, +0.1 C from the station mean2011: 5.0 C, 0.0 C from the station mean2012: 6.5 C, +1.5 C from the station mean2013: 5.4 C, +0.4 C from the station mean2014: 5.0 C, 0.0 C from the station mean2015: 6.5 C, +1.5 C from the station mean2016: 6.4 C, +1.4 C from the station mean2017: 5.7 C, +0.7 C from the station mean2018: 5.1 C, 0.0 C from the station mean2019: 4.0 C, -1.0 C from the station mean2020: 5.7 C, +0.6 C from the station mean2021: 5.9 C, +0.9 C from the station mean2022: 5.0 C, 0.0 C from the station mean2023: 5.6 C, +0.6 C from the station mean2024: 6.4 C, +1.4 C from the station mean2025: 6.3 C, +1.2 C from the station mean19911995200020052010201520202025
One stripe for each of 34 complete years at Porcupine, 1991 to 2025. Blue stripes are years cooler than the station's own mean of 5.0 C (41.0 F); red stripes are warmer. The coolest year was 1993, at 1.8 C (35.2 F), and the warmest was 2012, at 6.5 C (43.7 F). The strongest colour marks a difference of 3.3 C (5.9 F).
Annual mean temperature at Porcupine as warming stripes, 1991 to 2025
YearAnnual mean temperatureDifference from the station mean
19914.5 C-0.47 C
19931.8 C-3.24 C
19943.8 C-1.21 C
19953.1 C-1.93 C
19962.4 C-2.58 C
19972.8 C-2.22 C
19984.8 C-0.26 C
19995.7 C+0.64 C
20005.1 C+0.12 C
20015.9 C+0.86 C
20024.2 C-0.79 C
20035.7 C+0.67 C
20044.9 C-0.13 C
20054.6 C-0.40 C
20066.2 C+1.15 C
20076.1 C+1.05 C
20084.7 C-0.29 C
20094.7 C-0.31 C
20105.1 C+0.07 C
20115.0 C-0.02 C
20126.5 C+1.51 C
20135.4 C+0.43 C
20145.0 C-0.01 C
20156.5 C+1.50 C
20166.4 C+1.38 C
20175.7 C+0.73 C
20185.1 C+0.05 C
20194.0 C-1.01 C
20205.7 C+0.64 C
20215.9 C+0.90 C
20225.0 C+0.02 C
20235.6 C+0.60 C
20246.4 C+1.36 C
20256.3 C+1.25 C

The annual mean temperature here has risen by 0.7 C (0.4 to 1.1) per decade over 1991 to 2025. In Fahrenheit: 1.3 F (0.7 to 1.9) per decade. The slope is a straight line fitted to 34 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Porcupine
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.7 C (0.4 to 1.1) per decade1.3 F (0.7 to 1.9) per decade1991 to 202534Rise
Mean daily maximum0.6 C (0.2 to 0.9) per decade1.0 F (0.4 to 1.7) per decade1991 to 202534Rise
Mean daily minimum0.9 C (0.5 to 1.2) per decade1.6 F (1.0 to 2.2) per decade1991 to 202534Rise

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 Porcupine: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)34.1 C (93.4 F)200231.8 C (89.2 F)37
Coldest night (TNn)-36.3 C (-33.3 F)2022-28.5 C (-19.3 F)37
Wettest day (Rx1day)111.8 mm (4.4 in)197933.0 mm (1.3 in)49
Wettest five days (Rx5day)139.7 mm (5.5 in)197961.0 mm (2.4 in)49
Longest dry spell (CDD)74 days201722 days49

Hottest day (TXx)

Hottest day (TXx) at Porcupine by year The hottest day of the year at Porcupine, 1978 to 2026. The record is 34.1 C (93.4 F) in 2002, marked on the chart; the median year is 31.8 C (89.2 F). 283032343619801990200020102020Record: 34.1 C (93.4 F) in 2002
The hottest day of the year at Porcupine, 1978 to 2026. The record is 34.1 C (93.4 F) in 2002, marked on the chart; the median year is 31.8 C (89.2 F).
Hottest day (TXx) at Porcupine 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
199032.7 C (90.9 F)
199132.1 C (89.8 F)
199232.6 C (90.7 F)
199328.0 C (82.4 F)
199430.5 C (86.9 F)
199529.6 C (85.3 F)
199631.0 C (87.8 F)
199728.5 C (83.3 F)
199830.8 C (87.4 F)
199930.7 C (87.3 F)
200032.1 C (89.8 F)
200132.3 C (90.1 F)
200234.1 C (93.4 F)
200333.0 C (91.4 F)
200431.0 C (87.8 F)
200532.7 C (90.9 F)
200633.3 C (91.9 F)
200733.9 C (93.0 F)
200832.3 C (90.1 F)
200929.9 C (85.8 F)
201030.7 C (87.3 F)
201130.6 C (87.1 F)
201232.4 C (90.3 F)
201331.5 C (88.7 F)
201430.3 C (86.5 F)
201532.6 C (90.7 F)
201631.1 C (88.0 F)
201731.0 C (87.8 F)
201833.7 C (92.7 F)
201929.6 C (85.3 F)
202031.8 C (89.2 F)
202133.4 C (92.1 F)
202232.3 C (90.1 F)
202331.0 C (87.8 F)
202432.4 C (90.3 F)
202531.1 C (88.0 F)
202633.8 C (92.8 F)

Coldest night (TNn)

Coldest night (TNn) at Porcupine by year The coldest night of the year at Porcupine, 1978 to 2026. The record is -36.3 C (-33.3 F) in 2022, marked on the chart; the median year is -28.5 C (-19.3 F). -40-35-30-25-20-1519801990200020102020Record: -36.3 C (-33.3 F) in 2022
The coldest night of the year at Porcupine, 1978 to 2026. The record is -36.3 C (-33.3 F) in 2022, marked on the chart; the median year is -28.5 C (-19.3 F).
Coldest night (TNn) at Porcupine 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
1990-36.1 C (-33.0 F)
1991-27.3 C (-17.1 F)
1992-30.1 C (-22.2 F)
1993-30.0 C (-22.0 F)
1994-31.2 C (-24.2 F)
1995-28.4 C (-19.1 F)
1996-30.9 C (-23.6 F)
1997-32.8 C (-27.0 F)
1998-30.3 C (-22.5 F)
1999-19.8 C (-3.6 F)
2000-25.2 C (-13.4 F)
2001-21.7 C (-7.1 F)
2002-23.3 C (-9.9 F)
2003-26.9 C (-16.4 F)
2004-29.5 C (-21.1 F)
2005-29.1 C (-20.4 F)
2006-33.4 C (-28.1 F)
2007-26.8 C (-16.2 F)
2008-31.9 C (-25.4 F)
2009-29.7 C (-21.5 F)
2010-25.2 C (-13.4 F)
2011-27.1 C (-16.8 F)
2012-16.5 C (2.3 F)
2013-32.2 C (-26.0 F)
2014-31.7 C (-25.1 F)
2015-20.9 C (-5.6 F)
2016-26.7 C (-16.1 F)
2017-24.4 C (-11.9 F)
2018-25.9 C (-14.6 F)
2019-28.5 C (-19.3 F)
2020-20.3 C (-4.5 F)
2021-30.2 C (-22.4 F)
2022-36.3 C (-33.3 F)
2023-30.6 C (-23.1 F)
2024-34.3 C (-29.7 F)
2025-25.5 C (-13.9 F)
2026-19.1 C (-2.4 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Porcupine by year The wettest day of the year at Porcupine, 1978 to 2026. The record is 111.8 mm (4.4 in) in 1979, marked on the chart; the median year is 33.0 mm (1.3 in). 025507510012519801990200020102020Record: 111.8 mm (4.4 in) in 1979
The wettest day of the year at Porcupine, 1978 to 2026. The record is 111.8 mm (4.4 in) in 1979, marked on the chart; the median year is 33.0 mm (1.3 in).
Wettest day (Rx1day) at Porcupine by year
YearWettest day (Rx1day)
197812.7 mm (0.5 in)
1979111.8 mm (4.4 in)
198038.1 mm (1.5 in)
198133.0 mm (1.3 in)
198227.9 mm (1.1 in)
198338.1 mm (1.5 in)
198438.1 mm (1.5 in)
198545.7 mm (1.8 in)
198635.6 mm (1.4 in)
198743.2 mm (1.7 in)
198845.7 mm (1.8 in)
198933.0 mm (1.3 in)
199033.0 mm (1.3 in)
199127.9 mm (1.1 in)
199245.7 mm (1.8 in)
199358.4 mm (2.3 in)
199422.9 mm (0.9 in)
199538.1 mm (1.5 in)
199617.8 mm (0.7 in)
199727.9 mm (1.1 in)
199858.4 mm (2.3 in)
199922.9 mm (0.9 in)
200027.9 mm (1.1 in)
200145.7 mm (1.8 in)
200225.4 mm (1.0 in)
200327.9 mm (1.1 in)
200438.1 mm (1.5 in)
200530.5 mm (1.2 in)
200638.1 mm (1.5 in)
200735.6 mm (1.4 in)
200843.2 mm (1.7 in)
200930.5 mm (1.2 in)
201027.9 mm (1.1 in)
201145.7 mm (1.8 in)
201233.0 mm (1.3 in)
201322.9 mm (0.9 in)
201427.9 mm (1.1 in)
201525.4 mm (1.0 in)
201630.5 mm (1.2 in)
201748.3 mm (1.9 in)
201827.9 mm (1.1 in)
201927.9 mm (1.1 in)
202025.4 mm (1.0 in)
202122.9 mm (0.9 in)
202230.5 mm (1.2 in)
202345.7 mm (1.8 in)
202458.4 mm (2.3 in)
202533.0 mm (1.3 in)
202643.2 mm (1.7 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Porcupine by year The wettest five days of the year at Porcupine, 1978 to 2026. The record is 139.7 mm (5.5 in) in 1979, marked on the chart; the median year is 61.0 mm (2.4 in). 05010015019801990200020102020Record: 139.7 mm (5.5 in) in 1979
The wettest five days of the year at Porcupine, 1978 to 2026. The record is 139.7 mm (5.5 in) in 1979, marked on the chart; the median year is 61.0 mm (2.4 in).
Wettest five days (Rx5day) at Porcupine by year
YearWettest five days (Rx5day)
197827.9 mm (1.1 in)
1979139.7 mm (5.5 in)
1980101.5 mm (4.0 in)
198171.1 mm (2.8 in)
198261.0 mm (2.4 in)
198366.0 mm (2.6 in)
198450.8 mm (2.0 in)
198553.4 mm (2.1 in)
198643.2 mm (1.7 in)
198763.4 mm (2.5 in)
198858.4 mm (2.3 in)
198958.4 mm (2.3 in)
199048.2 mm (1.9 in)
199176.2 mm (3.0 in)
1992111.8 mm (4.4 in)
199383.7 mm (3.3 in)
199443.2 mm (1.7 in)
199568.6 mm (2.7 in)
199643.2 mm (1.7 in)
199758.4 mm (2.3 in)
199888.9 mm (3.5 in)
199943.1 mm (1.7 in)
200050.7 mm (2.0 in)
200176.2 mm (3.0 in)
200258.4 mm (2.3 in)
200343.1 mm (1.7 in)
200489.0 mm (3.5 in)
200571.2 mm (2.8 in)
200671.1 mm (2.8 in)
200758.5 mm (2.3 in)
200891.4 mm (3.6 in)
200940.6 mm (1.6 in)
201050.8 mm (2.0 in)
201181.3 mm (3.2 in)
201283.8 mm (3.3 in)
201355.9 mm (2.2 in)
201473.6 mm (2.9 in)
201555.9 mm (2.2 in)
201655.8 mm (2.2 in)
201776.2 mm (3.0 in)
201863.5 mm (2.5 in)
201960.9 mm (2.4 in)
202058.4 mm (2.3 in)
202168.6 mm (2.7 in)
202258.3 mm (2.3 in)
202373.5 mm (2.9 in)
202481.3 mm (3.2 in)
202543.2 mm (1.7 in)
202688.8 mm (3.5 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Porcupine by year The longest dry spell of the year at Porcupine, 1978 to 2026. The record is 74 days in 2017, marked on the chart; the median year is 22 days. 02040608019801990200020102020Record: 74 days in 2017
The longest dry spell of the year at Porcupine, 1978 to 2026. The record is 74 days in 2017, marked on the chart; the median year is 22 days.
Longest dry spell (CDD) at Porcupine by year
YearLongest dry spell (CDD)
197821 days
197931 days
198021 days
198122 days
198219 days
198318 days
198421 days
198520 days
198621 days
198724 days
198857 days
198922 days
199034 days
199131 days
199218 days
199324 days
199422 days
199515 days
199627 days
199714 days
199826 days
199932 days
200033 days
200133 days
200213 days
200332 days
200416 days
200523 days
200630 days
200740 days
200818 days
200941 days
201020 days
201120 days
201241 days
201326 days
201422 days
201522 days
201637 days
201774 days
201823 days
201930 days
202019 days
202127 days
202215 days
202315 days
202413 days
202515 days
202614 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

34 years with a frost

Across 34 years with a frost, the median last spring frost at Porcupine falls on 29 May and the median first autumn frost on 23 September, which leaves a median of 120 days between them.

Fitted over all years, the growing season changes by +23.4 days per decade at this station.

Frost dates and growing season at Porcupine
MeasureMedian, all yearsEarliest periodRecent period (1996 to 2025)Recent against earliestFitted trend
Last spring frost29 Mayn/a27 Mayn/a-11.5 days per decade
First autumn frost23 Septembern/a25 Septembern/a+12.0 days per decade
Growing days120 daysn/a125 daysn/a+23.4 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

47 years, 1979 to 2025

A day with at least 33.0 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 91.4 mm (3.6 in) of rain is expected about once in 100 years.

Rainfall return levels at Porcupine: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years33.0 mm (1.3 in)
5 years43.9 mm (1.7 in)
10 years52.7 mm (2.1 in)
25 years66.0 mm (2.6 in)
50 years77.8 mm (3.1 in)Longer than the 47 years of record
100 years91.4 mm (3.6 in)Longer than the 47 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, 47 years of values from 1979 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: 111.8 mm (4.4 in) in 1979; 58.4 mm (2.3 in) in 1993; 58.4 mm (2.3 in) in 1998.

Download the Data

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