Thermopolis Weather Records (USC00488875)
Record envelope, standing records and threshold days for Thermopolis (USC00488875), Wyoming, United States, with 128 years of record.
Key Facts for Thermopolis
- Thermopolis (USC00488875) is a weather station in Wyoming, United States at 43.65 latitude and -108.20 longitude, 1,317 m (4,321 ft) above sea level.
- The station reports from 1899 to 2026, 128 years of record.
- 1,464 records set at Thermopolis still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Thermopolis tied a daily record high maximum temperature of 30.0 C (86.0 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: Wyoming, United States, 43.65 latitude, -108.20 longitude.
- Elevation: 1,317 m (4,321 ft).
- Period of record: 1899 to 2026, 128 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
28 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 19.4 C (66.9 F) | -42.2 C (-44.0 F) | 17.8 C (64.0 F) | -23.9 C (-11.0 F) |
| Feb | 21.1 C (70.0 F) | -41.1 C (-42.0 F) | 19.4 C (66.9 F) | -21.7 C (-7.1 F) |
| Mar | 28.9 C (84.0 F) | -33.3 C (-27.9 F) | 28.9 C (84.0 F) | -17.2 C (1.0 F) |
| Apr | 31.7 C (89.1 F) | -21.1 C (-6.0 F) | 30.0 C (86.0 F) | -7.2 C (19.0 F) |
| May | 36.7 C (98.1 F) | -11.1 C (12.0 F) | 35.0 C (95.0 F) | -2.2 C (28.0 F) |
| Jun | 40.6 C (105.1 F) | -4.4 C (24.1 F) | 36.7 C (98.1 F) | 4.4 C (39.9 F) |
| Jul | 42.8 C (109.0 F) | 1.1 C (34.0 F) | 42.8 C (109.0 F) | 8.9 C (48.0 F) |
| Aug | 41.1 C (106.0 F) | -5.0 C (23.0 F) | 40.6 C (105.1 F) | 6.1 C (43.0 F) |
| Sep | 40.0 C (104.0 F) | -13.9 C (7.0 F) | 33.9 C (93.0 F) | 3.9 C (39.0 F) |
| Oct | 33.3 C (91.9 F) | -23.9 C (-11.0 F) | 31.1 C (88.0 F) | 3.9 C (39.0 F) |
| Nov | 25.0 C (77.0 F) | -33.3 C (-27.9 F) | n/a | n/a |
| Dec | 25.6 C (78.1 F) | -38.9 C (-38.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1899 | 13 |
| 1900 | 15 |
| 1901 | 10 |
| 1902 | 16 |
| 1903 | 31 |
| 1904 | 12 |
| 1905 | 2 |
| 1906 | 15 |
| 1907 | 2 |
| 1908 | 21 |
| 1909 | 20 |
| 1910 | 26 |
| 1911 | 17 |
| 1912 | 16 |
| 1913 | 12 |
| 1914 | 9 |
| 1915 | 11 |
| 1916 | 41 |
| 1917 | 19 |
| 1918 | 20 |
| 1919 | 1 |
| 1920 | 18 |
| 1922 | 7 |
| 1923 | 11 |
| 1924 | 22 |
| 1925 | 11 |
| 1926 | 14 |
| 1927 | 11 |
| 1928 | 9 |
| 1929 | 16 |
| 1930 | 16 |
| 1931 | 16 |
| 1932 | 24 |
| 1933 | 19 |
| 1934 | 19 |
| 1935 | 22 |
| 1936 | 44 |
| 1937 | 21 |
| 1938 | 11 |
| 1939 | 30 |
| 1940 | 16 |
| 1941 | 10 |
| 1948 | 5 |
| 1949 | 20 |
| 1950 | 25 |
| 1951 | 20 |
| 1952 | 15 |
| 1953 | 16 |
| 1954 | 34 |
| 1955 | 18 |
| 1956 | 5 |
| 1957 | 7 |
| 1958 | 12 |
| 1959 | 15 |
| 1960 | 12 |
| 1961 | 8 |
| 1962 | 19 |
| 1963 | 17 |
| 1964 | 1 |
| 1990 | 16 |
| 1991 | 12 |
| 1992 | 17 |
| 1993 | 8 |
| 1994 | 8 |
| 1995 | 20 |
| 1996 | 19 |
| 1997 | 10 |
| 1998 | 9 |
| 1999 | 15 |
| 2000 | 14 |
| 2001 | 9 |
| 2002 | 9 |
| 2003 | 20 |
| 2004 | 6 |
| 2005 | 12 |
| 2006 | 17 |
| 2007 | 11 |
| 2008 | 12 |
| 2009 | 17 |
| 2010 | 9 |
| 2011 | 8 |
| 2012 | 16 |
| 2013 | 16 |
| 2014 | 15 |
| 2015 | 11 |
| 2016 | 9 |
| 2017 | 18 |
| 2018 | 5 |
| 2019 | 15 |
| 2020 | 24 |
| 2021 | 25 |
| 2022 | 21 |
| 2023 | 9 |
| 2024 | 11 |
| 2025 | 12 |
| 2026 | 34 |
All-Time Record Progression
2 new records| Date | Kind | Detail |
|---|---|---|
| 2023-08-18 | Record high minimum temperature | Record high minimum temperature 25.0 C (77.0 F) |
| 2026-07-12 | Record high maximum temperature | Record high maximum temperature 42.8 C (109.0 F) |
Wettest Day of Each Month
Sep: 125.5 mm (4.9 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 36.3 mm (1.4 in) | 16 January 1995 |
| Feb | 22.6 mm (0.9 in) | 28 February 2004 |
| Mar | 56.9 mm (2.2 in) | 20 March 1904 |
| Apr | 87.9 mm (3.5 in) | 6 April 1922 |
| May | 114.3 mm (4.5 in) | 4 May 1906 |
| Jun | 57.7 mm (2.3 in) | 2 June 1915 |
| Jul | 31.2 mm (1.2 in) | 26 July 2007 |
| Aug | 47.8 mm (1.9 in) | 12 August 1930 |
| Sep | 125.5 mm (4.9 in) | 30 September 1923 |
| Oct | 55.1 mm (2.2 in) | 30 October 1922 |
| Nov | 27.9 mm (1.1 in) | 11 November 1923 |
| Dec | 28.4 mm (1.1 in) | 19 December 1925 |
Period of Record Coverage
1899 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1899 | 245 | 67% | No |
| 1900 | 332 | 91% | Yes |
| 1901 | 313 | 86% | No |
| 1902 | 324 | 89% | No |
| 1903 | 277 | 76% | No |
| 1904 | 136 | 37% | No |
| 1905 | 57 | 16% | No |
| 1906 | 85 | 23% | No |
| 1907 | 61 | 17% | No |
| 1908 | 366 | 100% | Yes |
| 1909 | 363 | 99% | Yes |
| 1910 | 334 | 92% | Yes |
| 1911 | 365 | 100% | Yes |
| 1912 | 365 | 100% | Yes |
| 1913 | 363 | 99% | Yes |
| 1914 | 333 | 91% | Yes |
| 1915 | 364 | 100% | Yes |
| 1916 | 365 | 100% | Yes |
| 1917 | 334 | 92% | Yes |
| 1918 | 311 | 85% | No |
| 1919 | 74 | 20% | No |
| 1920 | 100 | 27% | No |
| 1921 | 60 | 16% | No |
| 1922 | 363 | 99% | Yes |
| 1923 | 361 | 99% | Yes |
| 1924 | 364 | 99% | Yes |
| 1925 | 365 | 100% | Yes |
| 1926 | 365 | 100% | Yes |
| 1927 | 365 | 100% | Yes |
| 1928 | 365 | 100% | Yes |
| 1929 | 296 | 81% | No |
| 1930 | 329 | 90% | Yes |
| 1931 | 364 | 100% | Yes |
| 1932 | 360 | 98% | Yes |
| 1933 | 333 | 91% | Yes |
| 1934 | 363 | 99% | Yes |
| 1935 | 364 | 100% | Yes |
| 1936 | 363 | 99% | Yes |
| 1937 | 363 | 99% | Yes |
| 1938 | 361 | 99% | Yes |
| 1939 | 363 | 99% | Yes |
| 1940 | 365 | 100% | Yes |
| 1941 | 365 | 100% | Yes |
| 1948 | 153 | 42% | No |
| 1949 | 362 | 99% | Yes |
| 1950 | 359 | 98% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 364 | 99% | Yes |
| 1953 | 363 | 99% | Yes |
| 1954 | 358 | 98% | Yes |
| 1955 | 360 | 99% | Yes |
| 1956 | 279 | 76% | No |
| 1957 | 287 | 79% | No |
| 1958 | 354 | 97% | Yes |
| 1959 | 357 | 98% | Yes |
| 1960 | 327 | 89% | No |
| 1961 | 360 | 99% | Yes |
| 1962 | 333 | 91% | Yes |
| 1963 | 362 | 99% | Yes |
| 1964 | 91 | 25% | No |
| 1990 | 214 | 59% | No |
| 1991 | 363 | 99% | Yes |
| 1992 | 358 | 98% | Yes |
| 1993 | 363 | 99% | Yes |
| 1994 | 363 | 99% | Yes |
| 1995 | 364 | 100% | Yes |
| 1996 | 362 | 99% | Yes |
| 1997 | 365 | 100% | Yes |
| 1998 | 363 | 99% | Yes |
| 1999 | 362 | 99% | Yes |
| 2000 | 361 | 99% | Yes |
| 2001 | 362 | 99% | Yes |
| 2002 | 360 | 99% | Yes |
| 2003 | 361 | 99% | Yes |
| 2004 | 353 | 96% | Yes |
| 2005 | 365 | 100% | Yes |
| 2006 | 359 | 98% | Yes |
| 2007 | 327 | 90% | No |
| 2008 | 353 | 96% | Yes |
| 2009 | 361 | 99% | Yes |
| 2010 | 364 | 100% | Yes |
| 2011 | 364 | 100% | Yes |
| 2012 | 366 | 100% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 364 | 100% | Yes |
| 2015 | 365 | 100% | Yes |
| 2016 | 366 | 100% | Yes |
| 2017 | 364 | 100% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 364 | 100% | Yes |
| 2022 | 365 | 100% | Yes |
| 2023 | 364 | 100% | Yes |
| 2024 | 366 | 100% | Yes |
| 2025 | 364 | 100% | Yes |
| 2026 | 281 | 77% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 9 October 2026 | Thermopolis, US | daily high max (Tie, Provisional) | 30.0 C (86.0 F) | tie | 116 years | 10 of 100 (Routine) |
| 6 October 2026 | Thermopolis, US | daily high max (Tie, Provisional) | 30.6 C (87.1 F) | tie | 68 years | 7 of 100 (Routine) |
| 5 October 2026 | Thermopolis, US | daily high max (Tie, Provisional) | 31.1 C (88.0 F) | tie | 1 year | 2 of 100 (Routine) |
| 28 September 2026 | Thermopolis, US | daily high min (Provisional) | 11.1 C (52.0 F) | 0.5 C (0.9 F) | 85 years | 36 of 100 (Notable) |
| 31 August 2026 | Thermopolis, US | daily rain (Provisional) | 4.1 mm (0.16 in) | 0.3 mm (0.01 in) | 25 years | 17 of 100 (Routine) |
| 2 August 2026 | Thermopolis, US | daily high max | 40.6 C (105.1 F) | 2.8 C (5.0 F) | 101 years | 47 of 100 (Notable) |
| 13 July 2026 | Thermopolis, US | daily high min | 23.3 C (73.9 F) | 3.9 C (7.0 F) | 109 years | 51 of 100 (Notable) |
| 12 July 2026 | Thermopolis, US | all-time high max | 42.8 C (109.0 F) | 1.1 C (2.0 F) | 96 years | 61 of 100 (Major) |
| 12 July 2026 | Thermopolis, US | daily high min | 23.9 C (75.0 F) | 3.9 C (7.0 F) | 68 years | 41 of 100 (Notable) |
| 11 July 2026 | Thermopolis, US | daily high max (Tie) | 40.6 C (105.1 F) | tie | 72 years | 7 of 100 (Routine) |
| 7 July 2026 | Thermopolis, US | daily high min (Tie) | 18.9 C (66.0 F) | tie | 103 years | 10 of 100 (Routine) |
| 6 June 2026 | Thermopolis, US | daily high max | 36.7 C (98.1 F) | 1.7 C (3.1 F) | 13 years | 17 of 100 (Routine) |
| 6 June 2026 | Thermopolis, US | daily high min (Tie) | 15.6 C (60.1 F) | tie | 5 years | 2 of 100 (Routine) |
| 29 May 2026 | Thermopolis, US | daily high min | 16.1 C (61.0 F) | 0.5 C (0.9 F) | 32 years | 20 of 100 (Routine) |
| 28 May 2026 | Thermopolis, US | daily high min | 15.6 C (60.1 F) | 1.2 C (2.2 F) | 21 years | 19 of 100 (Routine) |
| 25 May 2026 | Thermopolis, US | daily high max | 32.2 C (90.0 F) | 0.5 C (0.9 F) | 104 years | 40 of 100 (Notable) |
| 18 May 2026 | Thermopolis, US | daily low max | 7.8 C (46.0 F) | 2.2 C (4.0 F) | 76 years | 36 of 100 (Notable) |
| 14 May 2026 | Thermopolis, US | daily high max (Tie) | 32.8 C (91.0 F) | tie | 24 years | 4 of 100 (Routine) |
| 13 May 2026 | Thermopolis, US | daily high max | 35.0 C (95.0 F) | 1.7 C (3.1 F) | 12 years | 15 of 100 (Routine) |
| 11 May 2026 | Thermopolis, US | daily high max | 32.2 C (90.0 F) | 0.5 C (0.9 F) | 85 years | 35 of 100 (Notable) |
Climate Trend
70 complete years, 1908 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1908 | 7.6 C | -0.92 C |
| 1909 | 7.1 C | -1.38 C |
| 1911 | 7.7 C | -0.80 C |
| 1912 | 6.5 C | -2.00 C |
| 1913 | 7.2 C | -1.32 C |
| 1915 | 7.6 C | -0.87 C |
| 1916 | 6.1 C | -2.40 C |
| 1922 | 6.4 C | -2.12 C |
| 1923 | 7.4 C | -1.07 C |
| 1924 | 6.4 C | -2.10 C |
| 1925 | 8.1 C | -0.38 C |
| 1926 | 7.7 C | -0.82 C |
| 1927 | 7.4 C | -1.09 C |
| 1928 | 7.2 C | -1.34 C |
| 1931 | 7.7 C | -0.76 C |
| 1932 | 6.7 C | -1.84 C |
| 1934 | 9.8 C | +1.27 C |
| 1935 | 7.9 C | -0.56 C |
| 1936 | 7.9 C | -0.60 C |
| 1937 | 7.5 C | -0.96 C |
| 1938 | 8.3 C | -0.22 C |
| 1939 | 8.5 C | +0.01 C |
| 1940 | 8.9 C | +0.41 C |
| 1941 | 8.7 C | +0.18 C |
| 1949 | 7.5 C | -0.96 C |
| 1950 | 7.3 C | -1.16 C |
| 1951 | 6.5 C | -1.95 C |
| 1952 | 8.0 C | -0.50 C |
| 1953 | 8.7 C | +0.18 C |
| 1954 | 8.8 C | +0.29 C |
| 1955 | 6.6 C | -1.86 C |
| 1958 | 9.4 C | +0.86 C |
| 1959 | 8.2 C | -0.33 C |
| 1960 | 8.6 C | +0.10 C |
| 1961 | 8.9 C | +0.38 C |
| 1963 | 8.5 C | -0.03 C |
| 1991 | 8.9 C | +0.38 C |
| 1992 | 9.6 C | +1.06 C |
| 1993 | 7.3 C | -1.21 C |
| 1994 | 10.2 C | +1.68 C |
| 1995 | 9.2 C | +0.72 C |
| 1996 | 8.4 C | -0.07 C |
| 1997 | 9.1 C | +0.65 C |
| 1998 | 9.5 C | +1.00 C |
| 1999 | 10.6 C | +2.09 C |
| 2000 | 9.7 C | +1.23 C |
| 2001 | 10.0 C | +1.55 C |
| 2002 | 9.0 C | +0.46 C |
| 2003 | 9.8 C | +1.30 C |
| 2004 | 9.5 C | +0.98 C |
| 2005 | 9.7 C | +1.20 C |
| 2006 | 10.5 C | +2.05 C |
| 2008 | 8.1 C | -0.37 C |
| 2009 | 8.1 C | -0.42 C |
| 2010 | 8.8 C | +0.31 C |
| 2011 | 8.2 C | -0.28 C |
| 2012 | 10.6 C | +2.13 C |
| 2013 | 8.3 C | -0.23 C |
| 2014 | 8.4 C | -0.11 C |
| 2015 | 9.9 C | +1.44 C |
| 2016 | 10.0 C | +1.49 C |
| 2017 | 9.2 C | +0.74 C |
| 2018 | 8.6 C | +0.13 C |
| 2019 | 7.7 C | -0.77 C |
| 2020 | 9.7 C | +1.21 C |
| 2021 | 10.0 C | +1.55 C |
| 2022 | 8.8 C | +0.31 C |
| 2023 | 9.0 C | +0.50 C |
| 2024 | 10.4 C | +1.86 C |
| 2025 | 10.3 C | +1.81 C |
The annual mean temperature here has risen by 0.2 C (0.2 to 0.3) per decade over 1908 to 2025. In Fahrenheit: 0.4 F (0.3 to 0.5) per decade. The slope is a straight line fitted to 70 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.2 C (0.2 to 0.3) per decade | 0.4 F (0.3 to 0.5) per decade | 1908 to 2025 | 70 | Rise |
| Mean daily maximum | 0.11 C (0.05 to 0.18) per decade | 0.2 F (0.1 to 0.3) per decade | 1908 to 2025 | 70 | Rise |
| Mean daily minimum | 0.3 C (0.3 to 0.4) per decade | 0.6 F (0.5 to 0.6) per decade | 1908 to 2025 | 70 | Rise |
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
1899 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 42.8 C (109.0 F) | 2026 | 38.9 C (102.0 F) | 97 |
| Coldest night (TNn) | -42.2 C (-44.0 F) | 1930 | -30.0 C (-22.0 F) | 97 |
| Wettest day (Rx1day) | 125.5 mm (4.9 in) | 1923 | 29.2 mm (1.1 in) | 97 |
| Wettest five days (Rx5day) | 133.9 mm (5.3 in) | 1904 | 38.1 mm (1.5 in) | 93 |
| Longest dry spell (CDD) | 100 days | 1935 | 31 days | 97 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1899 | 39.4 C (102.9 F) |
| 1900 | 41.1 C (106.0 F) |
| 1901 | 40.6 C (105.1 F) |
| 1902 | 40.0 C (104.0 F) |
| 1903 | 41.1 C (106.0 F) |
| 1904 | 36.1 C (97.0 F) |
| 1905 | 23.9 C (75.0 F) |
| 1906 | 26.1 C (79.0 F) |
| 1907 | 17.2 C (63.0 F) |
| 1908 | 38.3 C (100.9 F) |
| 1909 | 40.0 C (104.0 F) |
| 1910 | 40.6 C (105.1 F) |
| 1911 | 37.2 C (99.0 F) |
| 1912 | 36.1 C (97.0 F) |
| 1913 | 37.8 C (100.0 F) |
| 1914 | 36.7 C (98.1 F) |
| 1915 | 36.7 C (98.1 F) |
| 1916 | 40.0 C (104.0 F) |
| 1917 | 41.1 C (106.0 F) |
| 1918 | 38.9 C (102.0 F) |
| 1919 | 22.8 C (73.0 F) |
| 1920 | 41.1 C (106.0 F) |
| 1921 | 20.6 C (69.1 F) |
| 1922 | 38.3 C (100.9 F) |
| 1923 | 38.9 C (102.0 F) |
| 1924 | 37.8 C (100.0 F) |
| 1925 | 40.6 C (105.1 F) |
| 1926 | 37.8 C (100.0 F) |
| 1927 | 37.8 C (100.0 F) |
| 1928 | 38.9 C (102.0 F) |
| 1929 | 41.7 C (107.1 F) |
| 1930 | 38.3 C (100.9 F) |
| 1931 | 41.1 C (106.0 F) |
| 1932 | 37.8 C (100.0 F) |
| 1933 | 38.3 C (100.9 F) |
| 1934 | 38.9 C (102.0 F) |
| 1935 | 39.4 C (102.9 F) |
| 1936 | 40.6 C (105.1 F) |
| 1937 | 38.3 C (100.9 F) |
| 1938 | 39.4 C (102.9 F) |
| 1939 | 41.1 C (106.0 F) |
| 1940 | 41.1 C (106.0 F) |
| 1941 | 40.0 C (104.0 F) |
| 1948 | 36.1 C (97.0 F) |
| 1949 | 37.8 C (100.0 F) |
| 1950 | 37.2 C (99.0 F) |
| 1951 | 38.9 C (102.0 F) |
| 1952 | 38.3 C (100.9 F) |
| 1953 | 39.4 C (102.9 F) |
| 1954 | 40.6 C (105.1 F) |
| 1955 | 37.8 C (100.0 F) |
| 1956 | 38.9 C (102.0 F) |
| 1957 | 39.4 C (102.9 F) |
| 1958 | 37.8 C (100.0 F) |
| 1959 | 39.4 C (102.9 F) |
| 1960 | 38.3 C (100.9 F) |
| 1961 | 38.9 C (102.0 F) |
| 1962 | 37.2 C (99.0 F) |
| 1963 | 36.7 C (98.1 F) |
| 1964 | 16.7 C (62.1 F) |
| 1990 | 38.9 C (102.0 F) |
| 1991 | 37.8 C (100.0 F) |
| 1992 | 36.7 C (98.1 F) |
| 1993 | 36.7 C (98.1 F) |
| 1994 | 37.2 C (99.0 F) |
| 1995 | 38.9 C (102.0 F) |
| 1996 | 38.3 C (100.9 F) |
| 1997 | 36.7 C (98.1 F) |
| 1998 | 39.4 C (102.9 F) |
| 1999 | 37.8 C (100.0 F) |
| 2000 | 38.9 C (102.0 F) |
| 2001 | 38.9 C (102.0 F) |
| 2002 | 40.6 C (105.1 F) |
| 2003 | 39.4 C (102.9 F) |
| 2004 | 37.8 C (100.0 F) |
| 2005 | 41.1 C (106.0 F) |
| 2006 | 40.6 C (105.1 F) |
| 2007 | 39.4 C (102.9 F) |
| 2008 | 38.3 C (100.9 F) |
| 2009 | 36.1 C (97.0 F) |
| 2010 | 37.8 C (100.0 F) |
| 2011 | 37.8 C (100.0 F) |
| 2012 | 39.4 C (102.9 F) |
| 2013 | 37.8 C (100.0 F) |
| 2014 | 38.9 C (102.0 F) |
| 2015 | 37.2 C (99.0 F) |
| 2016 | 38.3 C (100.9 F) |
| 2017 | 37.2 C (99.0 F) |
| 2018 | 39.4 C (102.9 F) |
| 2019 | 37.8 C (100.0 F) |
| 2020 | 38.9 C (102.0 F) |
| 2021 | 40.6 C (105.1 F) |
| 2022 | 40.6 C (105.1 F) |
| 2023 | 38.3 C (100.9 F) |
| 2024 | 38.9 C (102.0 F) |
| 2025 | 39.4 C (102.9 F) |
| 2026 | 42.8 C (109.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1899 | -21.1 C (-6.0 F) |
| 1900 | -35.6 C (-32.1 F) |
| 1901 | -30.0 C (-22.0 F) |
| 1902 | -38.9 C (-38.0 F) |
| 1903 | -26.7 C (-16.1 F) |
| 1904 | -23.3 C (-9.9 F) |
| 1905 | -37.8 C (-36.0 F) |
| 1906 | -33.3 C (-27.9 F) |
| 1907 | -27.2 C (-17.0 F) |
| 1908 | -31.1 C (-24.0 F) |
| 1909 | -34.4 C (-29.9 F) |
| 1910 | -37.2 C (-35.0 F) |
| 1911 | -35.6 C (-32.1 F) |
| 1912 | -29.4 C (-20.9 F) |
| 1913 | -28.9 C (-20.0 F) |
| 1914 | -33.3 C (-27.9 F) |
| 1915 | -27.8 C (-18.0 F) |
| 1916 | -36.1 C (-33.0 F) |
| 1917 | -34.4 C (-29.9 F) |
| 1918 | -33.9 C (-29.0 F) |
| 1919 | -20.0 C (-4.0 F) |
| 1920 | -13.9 C (7.0 F) |
| 1921 | -27.2 C (-17.0 F) |
| 1922 | -35.6 C (-32.1 F) |
| 1923 | -36.7 C (-34.1 F) |
| 1924 | -38.9 C (-38.0 F) |
| 1925 | -26.1 C (-15.0 F) |
| 1926 | -35.0 C (-31.0 F) |
| 1927 | -31.7 C (-25.1 F) |
| 1928 | -27.8 C (-18.0 F) |
| 1929 | -35.0 C (-31.0 F) |
| 1930 | -42.2 C (-44.0 F) |
| 1931 | -26.1 C (-15.0 F) |
| 1932 | -35.0 C (-31.0 F) |
| 1933 | -41.1 C (-42.0 F) |
| 1934 | -26.7 C (-16.1 F) |
| 1935 | -34.4 C (-29.9 F) |
| 1936 | -40.6 C (-41.1 F) |
| 1937 | -33.9 C (-29.0 F) |
| 1938 | -31.1 C (-24.0 F) |
| 1939 | -36.1 C (-33.0 F) |
| 1940 | -32.8 C (-27.0 F) |
| 1941 | -27.8 C (-18.0 F) |
| 1948 | -26.7 C (-16.1 F) |
| 1949 | -39.4 C (-38.9 F) |
| 1950 | -31.1 C (-24.0 F) |
| 1951 | -33.9 C (-29.0 F) |
| 1952 | -31.7 C (-25.1 F) |
| 1953 | -24.4 C (-11.9 F) |
| 1954 | -25.0 C (-13.0 F) |
| 1955 | -33.3 C (-27.9 F) |
| 1956 | -31.7 C (-25.1 F) |
| 1957 | -28.3 C (-18.9 F) |
| 1958 | -19.4 C (-2.9 F) |
| 1959 | -34.4 C (-29.9 F) |
| 1960 | -27.2 C (-17.0 F) |
| 1961 | -28.3 C (-18.9 F) |
| 1962 | -35.0 C (-31.0 F) |
| 1963 | -38.9 C (-38.0 F) |
| 1964 | -26.1 C (-15.0 F) |
| 1990 | -37.2 C (-35.0 F) |
| 1991 | -26.1 C (-15.0 F) |
| 1992 | -26.7 C (-16.1 F) |
| 1993 | -30.0 C (-22.0 F) |
| 1994 | -23.3 C (-9.9 F) |
| 1995 | -23.3 C (-9.9 F) |
| 1996 | -30.6 C (-23.1 F) |
| 1997 | -25.6 C (-14.1 F) |
| 1998 | -32.2 C (-26.0 F) |
| 1999 | -16.7 C (1.9 F) |
| 2000 | -22.8 C (-9.0 F) |
| 2001 | -25.6 C (-14.1 F) |
| 2002 | -25.6 C (-14.1 F) |
| 2003 | -30.6 C (-23.1 F) |
| 2004 | -30.0 C (-22.0 F) |
| 2005 | -27.8 C (-18.0 F) |
| 2006 | -32.2 C (-26.0 F) |
| 2007 | -28.3 C (-18.9 F) |
| 2008 | -30.0 C (-22.0 F) |
| 2009 | -31.1 C (-24.0 F) |
| 2010 | -28.9 C (-20.0 F) |
| 2011 | -28.9 C (-20.0 F) |
| 2012 | -21.7 C (-7.1 F) |
| 2013 | -27.2 C (-17.0 F) |
| 2014 | -31.1 C (-24.0 F) |
| 2015 | -23.9 C (-11.0 F) |
| 2016 | -28.3 C (-18.9 F) |
| 2017 | -28.3 C (-18.9 F) |
| 2018 | -27.2 C (-17.0 F) |
| 2019 | -28.3 C (-18.9 F) |
| 2020 | -23.9 C (-11.0 F) |
| 2021 | -25.6 C (-14.1 F) |
| 2022 | -36.7 C (-34.1 F) |
| 2023 | -33.3 C (-27.9 F) |
| 2024 | -34.4 C (-29.9 F) |
| 2025 | -28.3 C (-18.9 F) |
| 2026 | -23.9 C (-11.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1899 | 6.6 mm (0.26 in) |
| 1900 | 25.9 mm (1.0 in) |
| 1901 | 17.3 mm (0.7 in) |
| 1902 | 24.1 mm (0.9 in) |
| 1903 | 38.1 mm (1.5 in) |
| 1904 | 56.9 mm (2.2 in) |
| 1905 | 52.6 mm (2.1 in) |
| 1906 | 114.3 mm (4.5 in) |
| 1907 | 7.4 mm (0.29 in) |
| 1908 | 54.1 mm (2.1 in) |
| 1909 | 19.8 mm (0.8 in) |
| 1910 | 34.8 mm (1.4 in) |
| 1911 | 29.2 mm (1.1 in) |
| 1912 | 45.2 mm (1.8 in) |
| 1913 | 30.0 mm (1.2 in) |
| 1914 | 35.6 mm (1.4 in) |
| 1915 | 57.7 mm (2.3 in) |
| 1916 | 16.5 mm (0.6 in) |
| 1917 | 36.3 mm (1.4 in) |
| 1918 | 19.8 mm (0.8 in) |
| 1919 | 0.0 mm (0.00 in) |
| 1920 | 13.5 mm (0.5 in) |
| 1921 | 9.4 mm (0.37 in) |
| 1922 | 87.9 mm (3.5 in) |
| 1923 | 125.5 mm (4.9 in) |
| 1924 | 44.2 mm (1.7 in) |
| 1925 | 48.3 mm (1.9 in) |
| 1926 | 40.1 mm (1.6 in) |
| 1927 | 18.8 mm (0.7 in) |
| 1928 | 43.2 mm (1.7 in) |
| 1929 | 34.3 mm (1.4 in) |
| 1930 | 47.8 mm (1.9 in) |
| 1931 | 33.0 mm (1.3 in) |
| 1932 | 38.4 mm (1.5 in) |
| 1933 | 44.5 mm (1.8 in) |
| 1934 | 20.3 mm (0.8 in) |
| 1935 | 45.7 mm (1.8 in) |
| 1936 | 19.1 mm (0.8 in) |
| 1937 | 41.9 mm (1.6 in) |
| 1938 | 23.6 mm (0.9 in) |
| 1939 | 45.2 mm (1.8 in) |
| 1940 | 21.8 mm (0.9 in) |
| 1941 | 35.6 mm (1.4 in) |
| 1948 | 20.3 mm (0.8 in) |
| 1949 | 22.1 mm (0.9 in) |
| 1950 | 23.6 mm (0.9 in) |
| 1951 | 29.7 mm (1.2 in) |
| 1952 | 36.8 mm (1.4 in) |
| 1953 | 38.1 mm (1.5 in) |
| 1954 | 23.4 mm (0.9 in) |
| 1955 | 22.1 mm (0.9 in) |
| 1956 | 9.4 mm (0.37 in) |
| 1957 | 30.5 mm (1.2 in) |
| 1958 | 27.9 mm (1.1 in) |
| 1959 | 21.1 mm (0.8 in) |
| 1960 | 16.5 mm (0.6 in) |
| 1961 | 20.3 mm (0.8 in) |
| 1962 | 19.1 mm (0.8 in) |
| 1963 | 50.8 mm (2.0 in) |
| 1964 | 17.8 mm (0.7 in) |
| 1990 | 16.5 mm (0.6 in) |
| 1991 | 29.7 mm (1.2 in) |
| 1992 | 27.7 mm (1.1 in) |
| 1993 | 29.2 mm (1.1 in) |
| 1994 | 39.4 mm (1.6 in) |
| 1995 | 36.3 mm (1.4 in) |
| 1996 | 26.4 mm (1.0 in) |
| 1997 | 21.6 mm (0.9 in) |
| 1998 | 30.0 mm (1.2 in) |
| 1999 | 22.4 mm (0.9 in) |
| 2000 | 26.9 mm (1.1 in) |
| 2001 | 19.8 mm (0.8 in) |
| 2002 | 15.2 mm (0.6 in) |
| 2003 | 26.2 mm (1.0 in) |
| 2004 | 30.5 mm (1.2 in) |
| 2005 | 46.2 mm (1.8 in) |
| 2006 | 17.3 mm (0.7 in) |
| 2007 | 31.2 mm (1.2 in) |
| 2008 | 55.9 mm (2.2 in) |
| 2009 | 21.8 mm (0.9 in) |
| 2010 | 41.9 mm (1.6 in) |
| 2011 | 34.8 mm (1.4 in) |
| 2012 | 8.1 mm (0.32 in) |
| 2013 | 48.3 mm (1.9 in) |
| 2014 | 18.5 mm (0.7 in) |
| 2015 | 15.2 mm (0.6 in) |
| 2016 | 21.1 mm (0.8 in) |
| 2017 | 36.3 mm (1.4 in) |
| 2018 | 27.7 mm (1.1 in) |
| 2019 | 30.2 mm (1.2 in) |
| 2020 | 27.2 mm (1.1 in) |
| 2021 | 21.6 mm (0.9 in) |
| 2022 | 24.6 mm (1.0 in) |
| 2023 | 50.3 mm (2.0 in) |
| 2024 | 33.0 mm (1.3 in) |
| 2025 | 31.5 mm (1.2 in) |
| 2026 | 20.8 mm (0.8 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1899 | 16.7 mm (0.7 in) |
| 1900 | 54.9 mm (2.2 in) |
| 1901 | 52.7 mm (2.1 in) |
| 1902 | 31.2 mm (1.2 in) |
| 1903 | 76.2 mm (3.0 in) |
| 1904 | 133.9 mm (5.3 in) |
| 1905 | 26.7 mm (1.1 in) |
| 1906 | 16.5 mm (0.6 in) |
| 1907 | 7.4 mm (0.29 in) |
| 1908 | 67.1 mm (2.6 in) |
| 1909 | 38.1 mm (1.5 in) |
| 1910 | 35.4 mm (1.4 in) |
| 1911 | 34.1 mm (1.3 in) |
| 1912 | 54.1 mm (2.1 in) |
| 1913 | 41.5 mm (1.6 in) |
| 1914 | 43.6 mm (1.7 in) |
| 1915 | 77.2 mm (3.0 in) |
| 1916 | 31.7 mm (1.2 in) |
| 1917 | 54.9 mm (2.2 in) |
| 1918 | 29.2 mm (1.1 in) |
| 1919 | 2.5 mm (0.10 in) |
| 1920 | 5.6 mm (0.22 in) |
| 1921 | n/a |
| 1922 | n/a |
| 1923 | 128.8 mm (5.1 in) |
| 1924 | 22.4 mm (0.9 in) |
| 1925 | n/a |
| 1926 | 71.6 mm (2.8 in) |
| 1927 | 31.9 mm (1.3 in) |
| 1928 | n/a |
| 1929 | 63.3 mm (2.5 in) |
| 1930 | 84.1 mm (3.3 in) |
| 1931 | 64.3 mm (2.5 in) |
| 1932 | 59.5 mm (2.3 in) |
| 1933 | 78.8 mm (3.1 in) |
| 1934 | 30.2 mm (1.2 in) |
| 1935 | 65.5 mm (2.6 in) |
| 1936 | 25.2 mm (1.0 in) |
| 1937 | 66.2 mm (2.6 in) |
| 1938 | 42.0 mm (1.7 in) |
| 1939 | 46.0 mm (1.8 in) |
| 1940 | 33.6 mm (1.3 in) |
| 1941 | 68.9 mm (2.7 in) |
| 1948 | 35.0 mm (1.4 in) |
| 1949 | 29.5 mm (1.2 in) |
| 1950 | 26.2 mm (1.0 in) |
| 1951 | 35.6 mm (1.4 in) |
| 1952 | 58.1 mm (2.3 in) |
| 1953 | 40.6 mm (1.6 in) |
| 1954 | 23.4 mm (0.9 in) |
| 1955 | 38.8 mm (1.5 in) |
| 1956 | 19.6 mm (0.8 in) |
| 1957 | 74.7 mm (2.9 in) |
| 1958 | 38.9 mm (1.5 in) |
| 1959 | 37.1 mm (1.5 in) |
| 1960 | 24.4 mm (1.0 in) |
| 1961 | 42.9 mm (1.7 in) |
| 1962 | 34.1 mm (1.3 in) |
| 1963 | 108.4 mm (4.3 in) |
| 1964 | 17.8 mm (0.7 in) |
| 1990 | 29.0 mm (1.1 in) |
| 1991 | 31.7 mm (1.2 in) |
| 1992 | 51.6 mm (2.0 in) |
| 1993 | 59.7 mm (2.4 in) |
| 1994 | 66.0 mm (2.6 in) |
| 1995 | 54.6 mm (2.1 in) |
| 1996 | 60.4 mm (2.4 in) |
| 1997 | 35.3 mm (1.4 in) |
| 1998 | 38.9 mm (1.5 in) |
| 1999 | 46.0 mm (1.8 in) |
| 2000 | 36.8 mm (1.4 in) |
| 2001 | 37.1 mm (1.5 in) |
| 2002 | 23.3 mm (0.9 in) |
| 2003 | 40.2 mm (1.6 in) |
| 2004 | 37.3 mm (1.5 in) |
| 2005 | 96.0 mm (3.8 in) |
| 2006 | 28.0 mm (1.1 in) |
| 2007 | 35.0 mm (1.4 in) |
| 2008 | 66.1 mm (2.6 in) |
| 2009 | 27.1 mm (1.1 in) |
| 2010 | 90.4 mm (3.6 in) |
| 2011 | 65.0 mm (2.6 in) |
| 2012 | 10.4 mm (0.4 in) |
| 2013 | 56.7 mm (2.2 in) |
| 2014 | 19.8 mm (0.8 in) |
| 2015 | 25.4 mm (1.0 in) |
| 2016 | 39.2 mm (1.5 in) |
| 2017 | 58.7 mm (2.3 in) |
| 2018 | 45.5 mm (1.8 in) |
| 2019 | 30.7 mm (1.2 in) |
| 2020 | 27.2 mm (1.1 in) |
| 2021 | 33.0 mm (1.3 in) |
| 2022 | 25.2 mm (1.0 in) |
| 2023 | 50.3 mm (2.0 in) |
| 2024 | 36.3 mm (1.4 in) |
| 2025 | 31.5 mm (1.2 in) |
| 2026 | 25.1 mm (1.0 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1899 | 30 days |
| 1900 | 32 days |
| 1901 | 37 days |
| 1902 | 60 days |
| 1903 | 21 days |
| 1904 | 30 days |
| 1905 | 30 days |
| 1906 | 17 days |
| 1907 | 25 days |
| 1908 | 42 days |
| 1909 | 29 days |
| 1910 | 42 days |
| 1911 | 36 days |
| 1912 | 28 days |
| 1913 | 36 days |
| 1914 | 45 days |
| 1915 | 41 days |
| 1916 | 31 days |
| 1917 | 65 days |
| 1918 | 20 days |
| 1919 | 31 days |
| 1920 | 14 days |
| 1921 | 1 day |
| 1922 | 1 day |
| 1923 | 11 days |
| 1924 | 1 day |
| 1925 | 2 days |
| 1926 | 2 days |
| 1927 | 17 days |
| 1928 | 1 day |
| 1929 | 2 days |
| 1930 | 2 days |
| 1931 | 37 days |
| 1932 | 89 days |
| 1933 | 56 days |
| 1934 | 48 days |
| 1935 | 100 days |
| 1936 | 41 days |
| 1937 | 40 days |
| 1938 | 36 days |
| 1939 | 54 days |
| 1940 | 52 days |
| 1941 | 20 days |
| 1948 | 31 days |
| 1949 | 50 days |
| 1950 | 49 days |
| 1951 | 37 days |
| 1952 | 77 days |
| 1953 | 34 days |
| 1954 | 46 days |
| 1955 | 39 days |
| 1956 | 27 days |
| 1957 | 40 days |
| 1958 | 50 days |
| 1959 | 29 days |
| 1960 | 28 days |
| 1961 | 32 days |
| 1962 | 53 days |
| 1963 | 60 days |
| 1964 | 22 days |
| 1990 | 25 days |
| 1991 | 20 days |
| 1992 | 47 days |
| 1993 | 28 days |
| 1994 | 44 days |
| 1995 | 22 days |
| 1996 | 44 days |
| 1997 | 31 days |
| 1998 | 24 days |
| 1999 | 30 days |
| 2000 | 26 days |
| 2001 | 27 days |
| 2002 | 25 days |
| 2003 | 45 days |
| 2004 | 25 days |
| 2005 | 35 days |
| 2006 | 33 days |
| 2007 | 46 days |
| 2008 | 27 days |
| 2009 | 41 days |
| 2010 | 23 days |
| 2011 | 30 days |
| 2012 | 41 days |
| 2013 | 27 days |
| 2014 | 30 days |
| 2015 | 40 days |
| 2016 | 74 days |
| 2017 | 30 days |
| 2018 | 37 days |
| 2019 | 28 days |
| 2020 | 44 days |
| 2021 | 49 days |
| 2022 | 24 days |
| 2023 | 31 days |
| 2024 | 40 days |
| 2025 | 48 days |
| 2026 | 25 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
70 years with a frostAcross 70 years with a frost, the median last spring frost at Thermopolis falls on 14 May and the median first autumn frost on 24 September, which leaves a median of 135 days between them.
In 1995 to 2025 the median growing season was 145 days. That is 25 days more than in 1908 to 1954.
Fitted over all years, the growing season changes by +3.6 days per decade at this station.
| Measure | Median, all years | Earliest period (1908 to 1954) | Recent period (1995 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 14 May | 19 May | 12 May | 7 days earlier | -1.6 days per decade |
| First autumn frost | 24 September | 18 September | 4 October | 16 days later | +2.0 days per decade |
| Growing days | 135 days | 120 days | 145 days | 25 days more | +3.6 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
66 years, 1901 to 2025A day with at least 28.5 mm (1.1 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.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 28.5 mm (1.1 in) | |
| 5 years | 38.9 mm (1.5 in) | |
| 10 years | 45.7 mm (1.8 in) | |
| 25 years | 54.0 mm (2.1 in) | |
| 50 years | 60.0 mm (2.4 in) | |
| 100 years | 65.8 mm (2.6 in) | Longer than the 66 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, 66 years of values from 1901 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: 57.7 mm (2.3 in) in 1915; 55.9 mm (2.2 in) in 2008; 54.1 mm (2.1 in) in 1908.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-15).