St. Mary Montana Weather Records (USR0000MSTM)
Record envelope, standing records and threshold days for St. Mary Montana (USR0000MSTM), Montana, United States, with 38 years of record.
Key Facts for St. Mary Montana
- St. Mary Montana (USR0000MSTM) is a weather station in Montana, United States at 48.74 latitude and -113.43 longitude, 1,390 m (4,560 ft) above sea level.
- The station reports from 1986 to 2023, 38 years of record.
- 1,464 records set at St. Mary Montana still stand.
- Records are tracked for tmax, tmin: an element needs 30 years of data to be eligible.
- St. Mary Montana set a daily record high minimum temperature of 13.3 C (55.9 F) on 9 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, 48.74 latitude, -113.43 longitude.
- Elevation: 1,390 m (4,560 ft).
- Period of record: 1986 to 2023, 38 years.
- Eligible elements: tmax, tmin.
Daily Record Envelope and 2026
16 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 15.6 C (60.1 F) | -40.6 C (-41.1 F) | 12.2 C (54.0 F) | -20.6 C (-5.1 F) |
| Feb | 16.1 C (61.0 F) | -40.6 C (-41.1 F) | 15.0 C (59.0 F) | -26.1 C (-15.0 F) |
| Mar | 22.2 C (72.0 F) | -37.8 C (-36.0 F) | 13.3 C (55.9 F) | -21.7 C (-7.1 F) |
| Apr | 25.0 C (77.0 F) | -25.0 C (-13.0 F) | 24.4 C (75.9 F) | -9.4 C (15.1 F) |
| May | 30.6 C (87.1 F) | -10.0 C (14.0 F) | 28.3 C (82.9 F) | -4.4 C (24.1 F) |
| Jun | 34.4 C (93.9 F) | -2.2 C (28.0 F) | 23.9 C (75.0 F) | -1.1 C (30.0 F) |
| Jul | 37.2 C (99.0 F) | -1.1 C (30.0 F) | 31.7 C (89.1 F) | 2.8 C (37.0 F) |
| Aug | 36.7 C (98.1 F) | -5.6 C (21.9 F) | 31.7 C (89.1 F) | 0.0 C (32.0 F) |
| Sep | 33.3 C (91.9 F) | -12.8 C (9.0 F) | 27.2 C (81.0 F) | -1.7 C (28.9 F) |
| Oct | 29.4 C (84.9 F) | -22.8 C (-9.0 F) | 21.7 C (71.1 F) | -3.3 C (26.1 F) |
| Nov | 20.0 C (68.0 F) | -31.1 C (-24.0 F) | n/a | n/a |
| Dec | 16.7 C (62.1 F) | -40.6 C (-41.1 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1986 | 46 |
| 1987 | 62 |
| 1988 | 37 |
| 1989 | 32 |
| 1990 | 35 |
| 1991 | 35 |
| 1992 | 53 |
| 1993 | 36 |
| 1994 | 28 |
| 1995 | 35 |
| 1996 | 27 |
| 1997 | 35 |
| 1998 | 27 |
| 1999 | 47 |
| 2000 | 29 |
| 2001 | 28 |
| 2002 | 57 |
| 2003 | 40 |
| 2004 | 41 |
| 2005 | 39 |
| 2006 | 34 |
| 2007 | 22 |
| 2008 | 54 |
| 2009 | 56 |
| 2010 | 32 |
| 2011 | 25 |
| 2012 | 33 |
| 2013 | 30 |
| 2014 | 43 |
| 2016 | 34 |
| 2017 | 34 |
| 2018 | 21 |
| 2019 | 35 |
| 2020 | 38 |
| 2021 | 38 |
| 2022 | 36 |
| 2023 | 37 |
| 2024 | 41 |
| 2025 | 32 |
| 2026 | 20 |
Period of Record Coverage
1986 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1986 | 336 | 92% | Yes |
| 1987 | 356 | 98% | Yes |
| 1988 | 357 | 98% | Yes |
| 1989 | 359 | 98% | Yes |
| 1990 | 359 | 98% | Yes |
| 1991 | 361 | 99% | Yes |
| 1992 | 364 | 99% | Yes |
| 1993 | 325 | 89% | No |
| 1994 | 341 | 93% | Yes |
| 1995 | 326 | 89% | No |
| 1996 | 232 | 63% | No |
| 1997 | 356 | 98% | Yes |
| 1998 | 362 | 99% | Yes |
| 1999 | 361 | 99% | Yes |
| 2000 | 364 | 99% | Yes |
| 2001 | 355 | 97% | Yes |
| 2002 | 364 | 100% | Yes |
| 2003 | 360 | 99% | Yes |
| 2004 | 364 | 99% | Yes |
| 2005 | 364 | 100% | Yes |
| 2006 | 363 | 99% | Yes |
| 2007 | 363 | 99% | Yes |
| 2008 | 365 | 100% | Yes |
| 2009 | 361 | 99% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 364 | 100% | Yes |
| 2012 | 360 | 98% | Yes |
| 2013 | 362 | 99% | Yes |
| 2014 | 342 | 94% | Yes |
| 2016 | 364 | 99% | Yes |
| 2017 | 363 | 99% | Yes |
| 2018 | 362 | 99% | Yes |
| 2019 | 363 | 99% | Yes |
| 2020 | 363 | 99% | Yes |
| 2021 | 356 | 98% | Yes |
| 2022 | 236 | 65% | No |
| 2023 | 360 | 99% | Yes |
| 2024 | 365 | 100% | Yes |
| 2025 | 360 | 99% | Yes |
| 2026 | 281 | 77% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 9 October 2026 | St. Mary Montana, US | daily high min (Provisional) | 13.3 C (55.9 F) | 1.6 C (2.9 F) | 35 years | 16 of 100 (Routine) |
| 5 October 2026 | St. Mary Montana, US | daily high min (Provisional) | 15.0 C (59.0 F) | 3.3 C (5.9 F) | 21 years | 15 of 100 (Routine) |
| 2 October 2026 | St. Mary Montana, US | daily high min (Provisional) | 7.2 C (45.0 F) | 0.5 C (0.9 F) | 28 years | 12 of 100 (Routine) |
| 22 August 2026 | St. Mary Montana, US | daily high max (Tie, Provisional) | 30.0 C (86.0 F) | tie | 12 years | 1 of 100 (Routine) |
| 4 August 2026 | St. Mary Montana, US | daily low min (Tie) | 0.0 C (32.0 F) | tie | 17 years | 2 of 100 (Routine) |
| 26 July 2026 | St. Mary Montana, US | daily high min | 18.3 C (64.9 F) | 2.2 C (4.0 F) | 35 years | 20 of 100 (Routine) |
| 25 July 2026 | St. Mary Montana, US | daily high max (Tie) | 31.7 C (89.1 F) | tie | 28 years | 3 of 100 (Routine) |
| 18 July 2026 | St. Mary Montana, US | daily high min | 15.0 C (59.0 F) | 1.1 C (2.0 F) | 19 years | 12 of 100 (Routine) |
| 28 June 2026 | St. Mary Montana, US | daily low max (Tie) | 11.7 C (53.1 F) | tie | 4 years | 1 of 100 (Routine) |
| 23 June 2026 | St. Mary Montana, US | daily low min (Tie) | 0.6 C (33.1 F) | tie | 3 years | 1 of 100 (Routine) |
| 14 June 2026 | St. Mary Montana, US | daily low min | -1.1 C (30.0 F) | 0.5 C (0.9 F) | 24 years | 12 of 100 (Routine) |
| 1 June 2026 | St. Mary Montana, US | daily low max | 6.7 C (44.1 F) | 1.1 C (2.0 F) | 39 years | 17 of 100 (Routine) |
| 24 May 2026 | St. Mary Montana, US | daily high min | 13.9 C (57.0 F) | 0.6 C (1.1 F) | 8 years | 7 of 100 (Routine) |
| 18 May 2026 | St. Mary Montana, US | daily low min (Tie) | -3.3 C (26.1 F) | tie | 23 years | 2 of 100 (Routine) |
| 17 May 2026 | St. Mary Montana, US | daily low min (Tie) | -2.8 C (27.0 F) | tie | 24 years | 2 of 100 (Routine) |
| 26 April 2026 | St. Mary Montana, US | daily low max | -3.3 C (26.1 F) | 4.4 C (7.9 F) | 24 years | 18 of 100 (Routine) |
| 26 April 2026 | St. Mary Montana, US | daily low min (Tie) | -6.7 C (19.9 F) | tie | 16 years | 2 of 100 (Routine) |
| 25 April 2026 | St. Mary Montana, US | daily low min | -6.1 C (21.0 F) | 1.1 C (2.0 F) | 37 years | 17 of 100 (Routine) |
| 24 April 2026 | St. Mary Montana, US | daily low max (Tie) | 2.2 C (36.0 F) | tie | 4 years | 1 of 100 (Routine) |
| 21 April 2026 | St. Mary Montana, US | daily high max | 24.4 C (75.9 F) | 2.2 C (4.0 F) | 32 years | 16 of 100 (Routine) |
Climate Trend
34 complete years, 1987 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1987 | 6.3 C | +1.31 C |
| 1988 | 5.6 C | +0.58 C |
| 1989 | 4.0 C | -1.02 C |
| 1990 | 4.4 C | -0.66 C |
| 1991 | 5.1 C | +0.09 C |
| 1992 | 5.6 C | +0.59 C |
| 1993 | 4.2 C | -0.84 C |
| 1994 | 5.4 C | +0.35 C |
| 1997 | 5.2 C | +0.22 C |
| 1998 | 5.8 C | +0.77 C |
| 1999 | 5.8 C | +0.82 C |
| 2000 | 4.6 C | -0.40 C |
| 2001 | 5.4 C | +0.38 C |
| 2002 | 4.2 C | -0.78 C |
| 2003 | 5.9 C | +0.89 C |
| 2004 | 5.6 C | +0.60 C |
| 2005 | 5.1 C | +0.08 C |
| 2006 | 5.4 C | +0.38 C |
| 2007 | 5.2 C | +0.21 C |
| 2008 | 4.1 C | -0.96 C |
| 2009 | 4.0 C | -1.07 C |
| 2010 | 4.5 C | -0.50 C |
| 2011 | 4.0 C | -1.05 C |
| 2012 | 5.0 C | -0.02 C |
| 2013 | 4.9 C | -0.10 C |
| 2016 | 6.1 C | +1.03 C |
| 2017 | 4.5 C | -0.48 C |
| 2018 | 4.1 C | -0.88 C |
| 2019 | 3.3 C | -1.68 C |
| 2020 | 5.1 C | +0.07 C |
| 2021 | 5.0 C | -0.01 C |
| 2023 | 5.9 C | +0.89 C |
| 2024 | 5.6 C | +0.60 C |
| 2025 | 5.7 C | +0.71 C |
The fitted trend in annual mean temperature here over 1987 to 2025 is -0.1 C (-0.3 to 0.2) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.5 to 0.3) per decade. The slope is a straight line fitted to 34 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | -0.1 C (-0.3 to 0.2) per decade | -0.1 F (-0.5 to 0.3) per decade | 1987 to 2025 | 34 | Not clearly different from zero |
| Mean daily maximum | -0.1 C (-0.3 to 0.2) per decade | -0.1 F (-0.6 to 0.3) per decade | 1987 to 2025 | 34 | Not clearly different from zero |
| Mean daily minimum | -0.04 C (-0.29 to 0.21) per decade | -0.1 F (-0.5 to 0.4) per decade | 1987 to 2025 | 34 | Not 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
1986 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 37.2 C (99.0 F) | 2002 | 33.3 C (91.9 F) | 40 |
| Coldest night (TNn) | -40.6 C (-41.1 F) | 1989 | -32.5 C (-26.5 F) | 40 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1986 | 31.7 C (89.1 F) |
| 1987 | 34.4 C (93.9 F) |
| 1988 | 33.9 C (93.0 F) |
| 1989 | 30.6 C (87.1 F) |
| 1990 | 32.8 C (91.0 F) |
| 1991 | 33.3 C (91.9 F) |
| 1992 | 32.2 C (90.0 F) |
| 1993 | 30.0 C (86.0 F) |
| 1994 | 34.4 C (93.9 F) |
| 1995 | 29.4 C (84.9 F) |
| 1996 | 33.9 C (93.0 F) |
| 1997 | 34.4 C (93.9 F) |
| 1998 | 34.4 C (93.9 F) |
| 1999 | 32.2 C (90.0 F) |
| 2000 | 33.9 C (93.0 F) |
| 2001 | 33.9 C (93.0 F) |
| 2002 | 37.2 C (99.0 F) |
| 2003 | 36.7 C (98.1 F) |
| 2004 | 33.9 C (93.0 F) |
| 2005 | 31.7 C (89.1 F) |
| 2006 | 34.4 C (93.9 F) |
| 2007 | 37.2 C (99.0 F) |
| 2008 | 35.6 C (96.1 F) |
| 2009 | 30.6 C (87.1 F) |
| 2010 | 30.6 C (87.1 F) |
| 2011 | 32.8 C (91.0 F) |
| 2012 | 32.2 C (90.0 F) |
| 2013 | 33.3 C (91.9 F) |
| 2014 | 32.2 C (90.0 F) |
| 2016 | 31.1 C (88.0 F) |
| 2017 | 33.9 C (93.0 F) |
| 2018 | 35.6 C (96.1 F) |
| 2019 | 33.3 C (91.9 F) |
| 2020 | 31.1 C (88.0 F) |
| 2021 | 34.4 C (93.9 F) |
| 2022 | 33.3 C (91.9 F) |
| 2023 | 33.9 C (93.0 F) |
| 2024 | 32.8 C (91.0 F) |
| 2025 | 31.1 C (88.0 F) |
| 2026 | 31.7 C (89.1 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1986 | -30.0 C (-22.0 F) |
| 1987 | -25.6 C (-14.1 F) |
| 1988 | -32.2 C (-26.0 F) |
| 1989 | -40.6 C (-41.1 F) |
| 1990 | -38.9 C (-38.0 F) |
| 1991 | -33.3 C (-27.9 F) |
| 1992 | -33.9 C (-29.0 F) |
| 1993 | -30.6 C (-23.1 F) |
| 1994 | -33.3 C (-27.9 F) |
| 1995 | -32.2 C (-26.0 F) |
| 1996 | -31.1 C (-24.0 F) |
| 1997 | -31.1 C (-24.0 F) |
| 1998 | -38.3 C (-36.9 F) |
| 1999 | -18.9 C (-2.0 F) |
| 2000 | -28.9 C (-20.0 F) |
| 2001 | -26.7 C (-16.1 F) |
| 2002 | -35.6 C (-32.1 F) |
| 2003 | -30.6 C (-23.1 F) |
| 2004 | -31.7 C (-25.1 F) |
| 2005 | -36.1 C (-33.0 F) |
| 2006 | -32.8 C (-27.0 F) |
| 2007 | -28.3 C (-18.9 F) |
| 2008 | -33.3 C (-27.9 F) |
| 2009 | -36.1 C (-33.0 F) |
| 2010 | -30.6 C (-23.1 F) |
| 2011 | -35.6 C (-32.1 F) |
| 2012 | -31.7 C (-25.1 F) |
| 2013 | -36.7 C (-34.1 F) |
| 2014 | -35.6 C (-32.1 F) |
| 2016 | -30.6 C (-23.1 F) |
| 2017 | -36.1 C (-33.0 F) |
| 2018 | -31.7 C (-25.1 F) |
| 2019 | -37.8 C (-36.0 F) |
| 2020 | -31.1 C (-24.0 F) |
| 2021 | -37.8 C (-36.0 F) |
| 2022 | -40.6 C (-41.1 F) |
| 2023 | -35.0 C (-31.0 F) |
| 2024 | -40.6 C (-41.1 F) |
| 2025 | -30.6 C (-23.1 F) |
| 2026 | -26.1 C (-15.0 F) |
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 frostAcross 34 years with a frost, the median last spring frost at St. Mary Montana falls on 15 June and the median first autumn frost on 3 September, which leaves a median of 82 days between them.
Fitted over all years, the growing season changes by +5.7 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1991 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 15 June | n/a | 15 June | n/a | -1.9 days per decade |
| First autumn frost | 3 September | n/a | 2 September | n/a | +3.8 days per decade |
| Growing days | 82 days | n/a | 82 days | n/a | +5.7 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.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-12 (12 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-13).