Coulee Dam 1 SW Weather Records (USC00451767)
Record envelope, standing records and threshold days for Coulee Dam 1 SW (USC00451767), Washington, United States, with 93 years of record.
Key Facts for Coulee Dam 1 SW
- Coulee Dam 1 SW (USC00451767) is a weather station in Washington, United States at 47.95 latitude and -119.00 longitude, 524 m (1,719 ft) above sea level.
- The station reports from 1934 to 2026, 93 years of record.
- 1,464 records set at Coulee Dam 1 SW still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Coulee Dam 1 SW set a daily record precipitation of 5.8 mm (0.23 in) on 29 August 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Washington, United States, 47.95 latitude, -119.00 longitude.
- Elevation: 524 m (1,719 ft).
- Period of record: 1934 to 2026, 93 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 13.9 C (57.0 F) | -27.2 C (-17.0 F) | 8.3 C (46.9 F) | -9.4 C (15.1 F) |
| Feb | 16.1 C (61.0 F) | -26.1 C (-15.0 F) | 13.9 C (57.0 F) | -10.6 C (12.9 F) |
| Mar | 23.3 C (73.9 F) | -18.3 C (-0.9 F) | 20.0 C (68.0 F) | -5.0 C (23.0 F) |
| Apr | 33.3 C (91.9 F) | -6.7 C (19.9 F) | 24.4 C (75.9 F) | -1.7 C (28.9 F) |
| May | 37.8 C (100.0 F) | -2.8 C (27.0 F) | 33.3 C (91.9 F) | 2.8 C (37.0 F) |
| Jun | 44.4 C (111.9 F) | 2.2 C (36.0 F) | 32.8 C (91.0 F) | 4.4 C (39.9 F) |
| Jul | 45.0 C (113.0 F) | 0.0 C (32.0 F) | 37.2 C (99.0 F) | 11.7 C (53.1 F) |
| Aug | 43.3 C (109.9 F) | 3.3 C (37.9 F) | 36.1 C (97.0 F) | 8.3 C (46.9 F) |
| Sep | 40.0 C (104.0 F) | -1.1 C (30.0 F) | 28.3 C (82.9 F) | 4.4 C (39.9 F) |
| Oct | 32.2 C (90.0 F) | -12.2 C (10.0 F) | 24.4 C (75.9 F) | 2.8 C (37.0 F) |
| Nov | 20.6 C (69.1 F) | -23.3 C (-9.9 F) | n/a | n/a |
| Dec | 18.9 C (66.0 F) | -26.7 C (-16.1 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1934 | 14 |
| 1935 | 24 |
| 1936 | 61 |
| 1937 | 25 |
| 1938 | 21 |
| 1939 | 39 |
| 1940 | 28 |
| 1941 | 26 |
| 1942 | 5 |
| 1943 | 22 |
| 1944 | 9 |
| 1945 | 26 |
| 1947 | 16 |
| 1948 | 14 |
| 1949 | 22 |
| 1950 | 44 |
| 1951 | 32 |
| 1952 | 10 |
| 1953 | 9 |
| 1954 | 17 |
| 1955 | 35 |
| 1956 | 10 |
| 1957 | 18 |
| 1958 | 17 |
| 1959 | 12 |
| 1960 | 15 |
| 1961 | 8 |
| 1962 | 11 |
| 1963 | 12 |
| 1964 | 14 |
| 1965 | 13 |
| 1966 | 9 |
| 1967 | 11 |
| 1968 | 28 |
| 1969 | 15 |
| 1970 | 17 |
| 1971 | 17 |
| 1972 | 30 |
| 1973 | 9 |
| 1974 | 13 |
| 1975 | 20 |
| 1976 | 7 |
| 1977 | 20 |
| 1978 | 7 |
| 1979 | 12 |
| 1980 | 11 |
| 1981 | 13 |
| 1982 | 11 |
| 1983 | 22 |
| 1984 | 15 |
| 1985 | 49 |
| 1986 | 21 |
| 1987 | 22 |
| 1988 | 9 |
| 1989 | 10 |
| 1990 | 13 |
| 1991 | 10 |
| 1992 | 24 |
| 1993 | 14 |
| 1994 | 5 |
| 1995 | 12 |
| 1996 | 7 |
| 1997 | 2 |
| 1998 | 9 |
| 1999 | 13 |
| 2000 | 9 |
| 2001 | 18 |
| 2002 | 30 |
| 2003 | 19 |
| 2004 | 6 |
| 2005 | 9 |
| 2006 | 11 |
| 2007 | 5 |
| 2008 | 14 |
| 2009 | 9 |
| 2010 | 7 |
| 2011 | 10 |
| 2012 | 5 |
| 2013 | 7 |
| 2014 | 17 |
| 2015 | 19 |
| 2016 | 11 |
| 2017 | 6 |
| 2018 | 5 |
| 2019 | 17 |
| 2020 | 17 |
| 2021 | 28 |
| 2022 | 17 |
| 2023 | 8 |
| 2024 | 10 |
| 2025 | 9 |
| 2026 | 5 |
All-Time Record Progression
10 new records| Date | Kind | Detail |
|---|---|---|
| 1968-12-29 | Record low maximum temperature | Record low maximum temperature -20.6 C (-5.1 F) |
| 1968-12-30 | Record low maximum temperature | Record low maximum temperature -21.7 C (-7.1 F) |
| 1975-01-12 | Record daily snowfall | Record daily snowfall 20.3 cm (8.0 in) |
| 1984-06-21 | Record daily precipitation | Record daily precipitation 40.6 mm (1.6 in) |
| 1985-07-10 | Record high minimum temperature | Record high minimum temperature 26.1 C (79.0 F) |
| 1993-01-01 | Record snow depth | Record snow depth 55.9 cm (22.0 in) |
| 1993-01-05 | Record snow depth | Record snow depth 58.4 cm (23.0 in) |
| 1996-01-24 | Record daily snowfall | Record daily snowfall 22.9 cm (9.0 in) |
| 1996-01-26 | Record daily snowfall | Record daily snowfall 24.1 cm (9.5 in) |
| 1996-06-27 | Record daily precipitation | Record daily precipitation 58.7 mm (2.3 in) |
Wettest Day of Each Month
Jun: 58.7 mm (2.3 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 21.8 mm (0.9 in) | 17 January 1945 |
| Feb | 24.6 mm (1.0 in) | 17 February 1940 |
| Mar | 38.1 mm (1.5 in) | 15 March 2012 |
| Apr | 27.9 mm (1.1 in) | 16 April 2011 |
| May | 34.3 mm (1.4 in) | 31 May 1941 |
| Jun | 58.7 mm (2.3 in) | 27 June 1996 |
| Jul | 32.8 mm (1.3 in) | 21 July 1965 |
| Aug | 31.0 mm (1.2 in) | 4 August 1948 |
| Sep | 35.1 mm (1.4 in) | 26 September 1948 |
| Oct | 34.5 mm (1.4 in) | 16 October 2006 |
| Nov | 28.4 mm (1.1 in) | 12 November 1973 |
| Dec | 24.1 mm (0.9 in) | 2 December 1996 |
Period of Record Coverage
1934 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1934 | 131 | 36% | No |
| 1935 | 281 | 77% | No |
| 1936 | 345 | 94% | Yes |
| 1937 | 351 | 96% | Yes |
| 1938 | 355 | 97% | Yes |
| 1939 | 361 | 99% | Yes |
| 1940 | 365 | 100% | Yes |
| 1941 | 365 | 100% | Yes |
| 1942 | 362 | 99% | Yes |
| 1943 | 337 | 92% | Yes |
| 1944 | 366 | 100% | Yes |
| 1945 | 363 | 99% | Yes |
| 1947 | 364 | 100% | Yes |
| 1948 | 366 | 100% | Yes |
| 1949 | 364 | 100% | Yes |
| 1950 | 323 | 88% | No |
| 1951 | 364 | 100% | Yes |
| 1952 | 365 | 100% | Yes |
| 1953 | 365 | 100% | Yes |
| 1954 | 365 | 100% | Yes |
| 1955 | 364 | 100% | Yes |
| 1956 | 364 | 99% | Yes |
| 1957 | 364 | 100% | Yes |
| 1958 | 364 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 365 | 100% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 366 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 365 | 100% | Yes |
| 1969 | 364 | 100% | Yes |
| 1970 | 364 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 362 | 99% | Yes |
| 1975 | 363 | 99% | Yes |
| 1976 | 363 | 99% | Yes |
| 1977 | 364 | 100% | Yes |
| 1978 | 349 | 96% | Yes |
| 1979 | 364 | 100% | Yes |
| 1980 | 363 | 99% | Yes |
| 1981 | 362 | 99% | Yes |
| 1982 | 344 | 94% | Yes |
| 1983 | 331 | 91% | Yes |
| 1984 | 348 | 95% | Yes |
| 1985 | 334 | 92% | Yes |
| 1986 | 329 | 90% | Yes |
| 1987 | 285 | 78% | No |
| 1988 | 335 | 92% | Yes |
| 1989 | 347 | 95% | Yes |
| 1990 | 354 | 97% | Yes |
| 1991 | 345 | 95% | Yes |
| 1992 | 354 | 97% | Yes |
| 1993 | 328 | 90% | No |
| 1994 | 349 | 96% | Yes |
| 1995 | 361 | 99% | Yes |
| 1996 | 354 | 97% | Yes |
| 1997 | 358 | 98% | Yes |
| 1998 | 298 | 82% | No |
| 1999 | 358 | 98% | Yes |
| 2000 | 328 | 90% | No |
| 2001 | 360 | 99% | Yes |
| 2002 | 352 | 96% | Yes |
| 2003 | 315 | 86% | No |
| 2004 | 258 | 70% | No |
| 2005 | 291 | 80% | No |
| 2006 | 350 | 96% | Yes |
| 2007 | 331 | 91% | Yes |
| 2008 | 351 | 96% | Yes |
| 2009 | 361 | 99% | Yes |
| 2010 | 357 | 98% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 364 | 99% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 363 | 99% | Yes |
| 2016 | 366 | 100% | Yes |
| 2017 | 363 | 99% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 362 | 99% | Yes |
| 2022 | 358 | 98% | Yes |
| 2023 | 357 | 98% | Yes |
| 2024 | 345 | 94% | Yes |
| 2025 | 356 | 98% | Yes |
| 2026 | 279 | 76% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 29 August 2026 | Coulee Dam 1 SW, US | daily rain (Provisional) | 5.8 mm (0.23 in) | 1.2 mm (0.05 in) | 83 years | 20 of 100 (Routine) |
| 15 June 2026 | Coulee Dam 1 SW, US | daily high min (Tie) | 18.3 C (64.9 F) | tie | 52 years | 6 of 100 (Routine) |
| 7 April 2026 | Coulee Dam 1 SW, US | daily high min | 10.0 C (50.0 F) | 1.1 C (2.0 F) | 29 years | 20 of 100 (Routine) |
| 2 April 2026 | Coulee Dam 1 SW, US | daily rain | 9.1 mm (0.36 in) | 1.5 mm (0.06 in) | 84 years | 20 of 100 (Routine) |
| 21 March 2026 | Coulee Dam 1 SW, US | daily high min (Tie) | 7.2 C (45.0 F) | tie | 11 years | 3 of 100 (Routine) |
| 20 March 2026 | Coulee Dam 1 SW, US | monthly high min (Tie) | 10.6 C (51.1 F) | tie | 19 years | 6 of 100 (Routine) |
| 19 March 2026 | Coulee Dam 1 SW, US | daily high min | 9.4 C (48.9 F) | 2.2 C (4.0 F) | 28 years | 23 of 100 (Routine) |
| 18 March 2026 | Coulee Dam 1 SW, US | daily high min | 8.3 C (46.9 F) | 2.2 C (4.0 F) | 84 years | 40 of 100 (Notable) |
| 8 March 2026 | Coulee Dam 1 SW, US | daily high min | 6.1 C (43.0 F) | 1.7 C (3.1 F) | 37 years | 24 of 100 (Routine) |
| 4 January 2026 | Coulee Dam 1 SW, US | daily rain | 10.4 mm (0.4 in) | 0.2 mm (0.01 in) | 4 years | 10 of 100 (Routine) |
| 15 December 2025 | Coulee Dam 1 SW, US | daily high min | 6.1 C (43.0 F) | 2.2 C (4.0 F) | 66 years | 32 of 100 (Routine) |
| 15 December 2025 | Coulee Dam 1 SW, US | daily high max (Tie) | 13.9 C (57.0 F) | tie | 86 years | 8 of 100 (Routine) |
| 12 December 2025 | Coulee Dam 1 SW, US | daily high min (Tie) | 4.4 C (39.9 F) | tie | 11 years | 3 of 100 (Routine) |
| 11 December 2025 | Coulee Dam 1 SW, US | daily high min (Tie) | 3.9 C (39.0 F) | tie | 86 years | 8 of 100 (Routine) |
| 17 November 2025 | Coulee Dam 1 SW, US | daily high min | 8.3 C (46.9 F) | 1.6 C (2.9 F) | 30 years | 21 of 100 (Routine) |
| 12 October 2025 | Coulee Dam 1 SW, US | daily rain | 9.7 mm (0.38 in) | 3.1 mm (0.12 in) | 4 years | 19 of 100 (Routine) |
| 7 September 2025 | Coulee Dam 1 SW, US | daily high min | 19.4 C (66.9 F) | 0.5 C (0.9 F) | 22 years | 16 of 100 (Routine) |
| 6 September 2025 | Coulee Dam 1 SW, US | daily high min | 17.2 C (63.0 F) | 0.5 C (0.9 F) | 18 years | 15 of 100 (Routine) |
| 5 September 2025 | Coulee Dam 1 SW, US | daily high min (Tie) | 18.3 C (64.9 F) | tie | 58 years | 6 of 100 (Routine) |
| 3 September 2025 | Coulee Dam 1 SW, US | daily high min (Tie) | 18.3 C (64.9 F) | tie | 2 years | 2 of 100 (Routine) |
Climate Trend
78 complete years, 1937 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1937 | 10.5 C | +0.43 C |
| 1938 | 12.1 C | +2.02 C |
| 1939 | 12.2 C | +2.08 C |
| 1940 | 12.1 C | +2.07 C |
| 1941 | 12.0 C | +1.91 C |
| 1942 | 10.1 C | +0.05 C |
| 1944 | 10.5 C | +0.38 C |
| 1945 | 10.6 C | +0.56 C |
| 1947 | 10.2 C | +0.13 C |
| 1948 | 8.5 C | -1.61 C |
| 1949 | 9.0 C | -1.04 C |
| 1951 | 9.0 C | -1.04 C |
| 1952 | 10.0 C | -0.04 C |
| 1953 | 10.4 C | +0.34 C |
| 1954 | 9.1 C | -0.93 C |
| 1955 | 7.9 C | -2.13 C |
| 1956 | 9.2 C | -0.91 C |
| 1957 | 9.1 C | -1.00 C |
| 1958 | 11.4 C | +1.34 C |
| 1959 | 8.9 C | -1.18 C |
| 1960 | 9.4 C | -0.69 C |
| 1961 | 10.4 C | +0.32 C |
| 1962 | 9.8 C | -0.26 C |
| 1963 | 10.2 C | +0.14 C |
| 1964 | 9.1 C | -0.98 C |
| 1965 | 10.0 C | -0.05 C |
| 1966 | 10.4 C | +0.30 C |
| 1967 | 11.0 C | +0.94 C |
| 1968 | 10.3 C | +0.25 C |
| 1969 | 9.5 C | -0.53 C |
| 1970 | 9.6 C | -0.43 C |
| 1971 | 9.5 C | -0.60 C |
| 1972 | 9.3 C | -0.74 C |
| 1973 | 10.3 C | +0.27 C |
| 1974 | 10.6 C | +0.50 C |
| 1975 | 9.1 C | -1.00 C |
| 1976 | 9.4 C | -0.66 C |
| 1977 | 9.7 C | -0.33 C |
| 1978 | 9.4 C | -0.67 C |
| 1979 | 10.2 C | +0.08 C |
| 1980 | 9.7 C | -0.33 C |
| 1981 | 10.5 C | +0.46 C |
| 1982 | 9.6 C | -0.50 C |
| 1983 | 10.1 C | +0.05 C |
| 1984 | 9.2 C | -0.86 C |
| 1985 | 8.5 C | -1.61 C |
| 1986 | 10.3 C | +0.24 C |
| 1988 | 10.8 C | +0.76 C |
| 1989 | 10.1 C | +0.07 C |
| 1990 | 10.8 C | +0.73 C |
| 1991 | 10.4 C | +0.34 C |
| 1992 | 11.1 C | +1.06 C |
| 1994 | 11.2 C | +1.08 C |
| 1995 | 10.5 C | +0.44 C |
| 1996 | 8.9 C | -1.15 C |
| 1997 | 9.7 C | -0.35 C |
| 1999 | 10.5 C | +0.44 C |
| 2001 | 9.5 C | -0.58 C |
| 2002 | 9.6 C | -0.46 C |
| 2006 | 10.3 C | +0.20 C |
| 2008 | 9.1 C | -0.99 C |
| 2009 | 9.3 C | -0.78 C |
| 2010 | 10.0 C | -0.03 C |
| 2011 | 9.3 C | -0.82 C |
| 2012 | 10.2 C | +0.17 C |
| 2013 | 10.0 C | -0.11 C |
| 2014 | 10.6 C | +0.52 C |
| 2015 | 11.7 C | +1.60 C |
| 2016 | 10.9 C | +0.80 C |
| 2017 | 9.5 C | -0.56 C |
| 2018 | 10.4 C | +0.37 C |
| 2019 | 9.3 C | -0.80 C |
| 2020 | 10.6 C | +0.51 C |
| 2021 | 11.1 C | +1.00 C |
| 2022 | 9.3 C | -0.80 C |
| 2023 | 10.7 C | +0.64 C |
| 2024 | 11.0 C | +0.96 C |
| 2025 | 11.4 C | +1.35 C |
The fitted trend in annual mean temperature here over 1937 to 2025 is 0.01 C (-0.07 to 0.08) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.01 F (-0.13 to 0.15) per decade. The slope is a straight line fitted to 78 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.01 C (-0.07 to 0.08) per decade | 0.01 F (-0.13 to 0.15) per decade | 1937 to 2025 | 78 | Not clearly different from zero |
| Mean daily maximum | -0.02 C (-0.11 to 0.07) per decade | -0.04 F (-0.20 to 0.12) per decade | 1937 to 2025 | 78 | Not clearly different from zero |
| Mean daily minimum | 0.03 C (-0.04 to 0.11) per decade | 0.1 F (-0.1 to 0.2) per decade | 1937 to 2025 | 78 | 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
1934 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 45.0 C (113.0 F) | 1939 | 38.3 C (100.9 F) | 92 |
| Coldest night (TNn) | -27.2 C (-17.0 F) | 1950 | -17.8 C (0.0 F) | 92 |
| Wettest day (Rx1day) | 58.7 mm (2.3 in) | 1996 | 19.0 mm (0.7 in) | 92 |
| Wettest five days (Rx5day) | 73.6 mm (2.9 in) | 2012 | 31.8 mm (1.3 in) | 92 |
| Longest dry spell (CDD) | 100 days | 1988 | 46 days | 92 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1934 | 40.0 C (104.0 F) |
| 1935 | 42.2 C (108.0 F) |
| 1936 | 42.2 C (108.0 F) |
| 1937 | 41.1 C (106.0 F) |
| 1938 | 42.8 C (109.0 F) |
| 1939 | 45.0 C (113.0 F) |
| 1940 | 40.0 C (104.0 F) |
| 1941 | 42.8 C (109.0 F) |
| 1942 | 39.4 C (102.9 F) |
| 1943 | 37.2 C (99.0 F) |
| 1944 | 38.9 C (102.0 F) |
| 1945 | 40.6 C (105.1 F) |
| 1947 | 37.8 C (100.0 F) |
| 1948 | 34.4 C (93.9 F) |
| 1949 | 37.2 C (99.0 F) |
| 1950 | 37.2 C (99.0 F) |
| 1951 | 37.8 C (100.0 F) |
| 1952 | 37.2 C (99.0 F) |
| 1953 | 37.2 C (99.0 F) |
| 1954 | 35.0 C (95.0 F) |
| 1955 | 38.9 C (102.0 F) |
| 1956 | 38.3 C (100.9 F) |
| 1957 | 33.9 C (93.0 F) |
| 1958 | 37.8 C (100.0 F) |
| 1959 | 38.9 C (102.0 F) |
| 1960 | 42.2 C (108.0 F) |
| 1961 | 43.3 C (109.9 F) |
| 1962 | 38.3 C (100.9 F) |
| 1963 | 36.1 C (97.0 F) |
| 1964 | 38.3 C (100.9 F) |
| 1965 | 37.8 C (100.0 F) |
| 1966 | 39.4 C (102.9 F) |
| 1967 | 39.4 C (102.9 F) |
| 1968 | 40.6 C (105.1 F) |
| 1969 | 37.2 C (99.0 F) |
| 1970 | 37.8 C (100.0 F) |
| 1971 | 40.0 C (104.0 F) |
| 1972 | 39.4 C (102.9 F) |
| 1973 | 38.9 C (102.0 F) |
| 1974 | 37.8 C (100.0 F) |
| 1975 | 40.6 C (105.1 F) |
| 1976 | 35.6 C (96.1 F) |
| 1977 | 39.4 C (102.9 F) |
| 1978 | 37.8 C (100.0 F) |
| 1979 | 40.6 C (105.1 F) |
| 1980 | 37.8 C (100.0 F) |
| 1981 | 38.3 C (100.9 F) |
| 1982 | 37.8 C (100.0 F) |
| 1983 | 36.1 C (97.0 F) |
| 1984 | 39.4 C (102.9 F) |
| 1985 | 41.7 C (107.1 F) |
| 1986 | 37.8 C (100.0 F) |
| 1987 | 36.7 C (98.1 F) |
| 1988 | 39.4 C (102.9 F) |
| 1989 | 37.8 C (100.0 F) |
| 1990 | 38.3 C (100.9 F) |
| 1991 | 36.1 C (97.0 F) |
| 1992 | 38.9 C (102.0 F) |
| 1993 | 33.3 C (91.9 F) |
| 1994 | 40.0 C (104.0 F) |
| 1995 | 36.1 C (97.0 F) |
| 1996 | 37.8 C (100.0 F) |
| 1997 | 37.2 C (99.0 F) |
| 1998 | 40.0 C (104.0 F) |
| 1999 | 37.2 C (99.0 F) |
| 2000 | 37.8 C (100.0 F) |
| 2001 | 37.8 C (100.0 F) |
| 2002 | 39.4 C (102.9 F) |
| 2003 | 40.0 C (104.0 F) |
| 2004 | 40.0 C (104.0 F) |
| 2005 | 37.8 C (100.0 F) |
| 2006 | 41.7 C (107.1 F) |
| 2007 | 38.3 C (100.9 F) |
| 2008 | 40.0 C (104.0 F) |
| 2009 | 39.4 C (102.9 F) |
| 2010 | 36.7 C (98.1 F) |
| 2011 | 35.0 C (95.0 F) |
| 2012 | 36.7 C (98.1 F) |
| 2013 | 38.3 C (100.9 F) |
| 2014 | 38.3 C (100.9 F) |
| 2015 | 40.6 C (105.1 F) |
| 2016 | 36.7 C (98.1 F) |
| 2017 | 36.7 C (98.1 F) |
| 2018 | 39.4 C (102.9 F) |
| 2019 | 37.2 C (99.0 F) |
| 2020 | 38.9 C (102.0 F) |
| 2021 | 44.4 C (111.9 F) |
| 2022 | 41.1 C (106.0 F) |
| 2023 | 39.4 C (102.9 F) |
| 2024 | 39.4 C (102.9 F) |
| 2025 | 38.3 C (100.9 F) |
| 2026 | 37.2 C (99.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1934 | -7.2 C (19.0 F) |
| 1935 | -23.3 C (-9.9 F) |
| 1936 | -23.9 C (-11.0 F) |
| 1937 | -25.0 C (-13.0 F) |
| 1938 | -9.4 C (15.1 F) |
| 1939 | -16.7 C (1.9 F) |
| 1940 | -11.1 C (12.0 F) |
| 1941 | -8.9 C (16.0 F) |
| 1942 | -13.3 C (8.1 F) |
| 1943 | -25.6 C (-14.1 F) |
| 1944 | -12.8 C (9.0 F) |
| 1945 | -11.7 C (10.9 F) |
| 1947 | -18.3 C (-0.9 F) |
| 1948 | -18.9 C (-2.0 F) |
| 1949 | -22.8 C (-9.0 F) |
| 1950 | -27.2 C (-17.0 F) |
| 1951 | -18.9 C (-2.0 F) |
| 1952 | -22.2 C (-8.0 F) |
| 1953 | -6.7 C (19.9 F) |
| 1954 | -22.8 C (-9.0 F) |
| 1955 | -17.8 C (0.0 F) |
| 1956 | -20.6 C (-5.1 F) |
| 1957 | -26.1 C (-15.0 F) |
| 1958 | -11.7 C (10.9 F) |
| 1959 | -19.4 C (-2.9 F) |
| 1960 | -16.7 C (1.9 F) |
| 1961 | -15.6 C (3.9 F) |
| 1962 | -21.7 C (-7.1 F) |
| 1963 | -18.3 C (-0.9 F) |
| 1964 | -25.0 C (-13.0 F) |
| 1965 | -11.7 C (10.9 F) |
| 1966 | -12.2 C (10.0 F) |
| 1967 | -12.8 C (9.0 F) |
| 1968 | -26.7 C (-16.1 F) |
| 1969 | -23.3 C (-9.9 F) |
| 1970 | -12.8 C (9.0 F) |
| 1971 | -16.7 C (1.9 F) |
| 1972 | -22.8 C (-9.0 F) |
| 1973 | -17.8 C (0.0 F) |
| 1974 | -19.4 C (-2.9 F) |
| 1975 | -16.7 C (1.9 F) |
| 1976 | -11.1 C (12.0 F) |
| 1977 | -16.7 C (1.9 F) |
| 1978 | -23.9 C (-11.0 F) |
| 1979 | -23.3 C (-9.9 F) |
| 1980 | -22.2 C (-8.0 F) |
| 1981 | -13.3 C (8.1 F) |
| 1982 | -21.1 C (-6.0 F) |
| 1983 | -23.9 C (-11.0 F) |
| 1984 | -20.0 C (-4.0 F) |
| 1985 | -23.3 C (-9.9 F) |
| 1986 | -18.9 C (-2.0 F) |
| 1987 | -11.7 C (10.9 F) |
| 1988 | -16.7 C (1.9 F) |
| 1989 | -20.6 C (-5.1 F) |
| 1990 | -25.0 C (-13.0 F) |
| 1991 | -18.3 C (-0.9 F) |
| 1992 | -13.9 C (7.0 F) |
| 1993 | -23.3 C (-9.9 F) |
| 1994 | -13.9 C (7.0 F) |
| 1995 | -14.4 C (6.1 F) |
| 1996 | -25.0 C (-13.0 F) |
| 1997 | -16.7 C (1.9 F) |
| 1998 | -15.6 C (3.9 F) |
| 1999 | -9.4 C (15.1 F) |
| 2000 | -14.4 C (6.1 F) |
| 2001 | -12.8 C (9.0 F) |
| 2002 | -11.7 C (10.9 F) |
| 2003 | -11.1 C (12.0 F) |
| 2004 | -5.6 C (21.9 F) |
| 2005 | -22.2 C (-8.0 F) |
| 2006 | -17.8 C (0.0 F) |
| 2007 | -15.6 C (3.9 F) |
| 2008 | -20.0 C (-4.0 F) |
| 2009 | -17.2 C (1.0 F) |
| 2010 | -18.9 C (-2.0 F) |
| 2011 | -20.0 C (-4.0 F) |
| 2012 | -16.1 C (3.0 F) |
| 2013 | -16.7 C (1.9 F) |
| 2014 | -20.0 C (-4.0 F) |
| 2015 | -13.9 C (7.0 F) |
| 2016 | -17.2 C (1.0 F) |
| 2017 | -20.6 C (-5.1 F) |
| 2018 | -13.9 C (7.0 F) |
| 2019 | -18.3 C (-0.9 F) |
| 2020 | -15.6 C (3.9 F) |
| 2021 | -17.8 C (0.0 F) |
| 2022 | -23.3 C (-9.9 F) |
| 2023 | -13.9 C (7.0 F) |
| 2024 | -22.8 C (-9.0 F) |
| 2025 | -15.6 C (3.9 F) |
| 2026 | -10.6 C (12.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1934 | 16.5 mm (0.6 in) |
| 1935 | 11.4 mm (0.4 in) |
| 1936 | 25.4 mm (1.0 in) |
| 1937 | 32.0 mm (1.3 in) |
| 1938 | 16.0 mm (0.6 in) |
| 1939 | 16.5 mm (0.6 in) |
| 1940 | 24.6 mm (1.0 in) |
| 1941 | 34.3 mm (1.4 in) |
| 1942 | 29.5 mm (1.2 in) |
| 1943 | 17.3 mm (0.7 in) |
| 1944 | 23.6 mm (0.9 in) |
| 1945 | 21.8 mm (0.9 in) |
| 1947 | 15.2 mm (0.6 in) |
| 1948 | 35.1 mm (1.4 in) |
| 1949 | 13.0 mm (0.5 in) |
| 1950 | 22.9 mm (0.9 in) |
| 1951 | 25.9 mm (1.0 in) |
| 1952 | 20.8 mm (0.8 in) |
| 1953 | 11.2 mm (0.4 in) |
| 1954 | 18.0 mm (0.7 in) |
| 1955 | 14.5 mm (0.6 in) |
| 1956 | 20.3 mm (0.8 in) |
| 1957 | 21.6 mm (0.9 in) |
| 1958 | 17.3 mm (0.7 in) |
| 1959 | 17.8 mm (0.7 in) |
| 1960 | 16.8 mm (0.7 in) |
| 1961 | 17.5 mm (0.7 in) |
| 1962 | 25.4 mm (1.0 in) |
| 1963 | 30.0 mm (1.2 in) |
| 1964 | 17.0 mm (0.7 in) |
| 1965 | 32.8 mm (1.3 in) |
| 1966 | 13.2 mm (0.5 in) |
| 1967 | 10.7 mm (0.4 in) |
| 1968 | 22.4 mm (0.9 in) |
| 1969 | 17.3 mm (0.7 in) |
| 1970 | 13.5 mm (0.5 in) |
| 1971 | 15.0 mm (0.6 in) |
| 1972 | 31.2 mm (1.2 in) |
| 1973 | 28.4 mm (1.1 in) |
| 1974 | 14.5 mm (0.6 in) |
| 1975 | 21.8 mm (0.9 in) |
| 1976 | 12.7 mm (0.5 in) |
| 1977 | 13.0 mm (0.5 in) |
| 1978 | 19.3 mm (0.8 in) |
| 1979 | 14.5 mm (0.6 in) |
| 1980 | 34.3 mm (1.4 in) |
| 1981 | 18.3 mm (0.7 in) |
| 1982 | 14.5 mm (0.6 in) |
| 1983 | 18.0 mm (0.7 in) |
| 1984 | 40.6 mm (1.6 in) |
| 1985 | 19.1 mm (0.8 in) |
| 1986 | 21.8 mm (0.9 in) |
| 1987 | 21.8 mm (0.9 in) |
| 1988 | 12.7 mm (0.5 in) |
| 1989 | 24.6 mm (1.0 in) |
| 1990 | 22.9 mm (0.9 in) |
| 1991 | 25.4 mm (1.0 in) |
| 1992 | 15.2 mm (0.6 in) |
| 1993 | 23.6 mm (0.9 in) |
| 1994 | 13.5 mm (0.5 in) |
| 1995 | 24.1 mm (0.9 in) |
| 1996 | 58.7 mm (2.3 in) |
| 1997 | 30.5 mm (1.2 in) |
| 1998 | 13.2 mm (0.5 in) |
| 1999 | 15.7 mm (0.6 in) |
| 2000 | 22.9 mm (0.9 in) |
| 2001 | 14.0 mm (0.6 in) |
| 2002 | 17.3 mm (0.7 in) |
| 2003 | 19.6 mm (0.8 in) |
| 2004 | 14.2 mm (0.6 in) |
| 2005 | 23.9 mm (0.9 in) |
| 2006 | 34.5 mm (1.4 in) |
| 2007 | 10.2 mm (0.4 in) |
| 2008 | 14.0 mm (0.6 in) |
| 2009 | 10.9 mm (0.4 in) |
| 2010 | 21.8 mm (0.9 in) |
| 2011 | 27.9 mm (1.1 in) |
| 2012 | 38.1 mm (1.5 in) |
| 2013 | 21.3 mm (0.8 in) |
| 2014 | 19.3 mm (0.8 in) |
| 2015 | 18.8 mm (0.7 in) |
| 2016 | 16.0 mm (0.6 in) |
| 2017 | 17.5 mm (0.7 in) |
| 2018 | 15.2 mm (0.6 in) |
| 2019 | 26.7 mm (1.1 in) |
| 2020 | 19.6 mm (0.8 in) |
| 2021 | 16.5 mm (0.6 in) |
| 2022 | 22.6 mm (0.9 in) |
| 2023 | 19.8 mm (0.8 in) |
| 2024 | 18.3 mm (0.7 in) |
| 2025 | 10.9 mm (0.4 in) |
| 2026 | 13.7 mm (0.5 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1934 | 24.2 mm (1.0 in) |
| 1935 | 19.3 mm (0.8 in) |
| 1936 | 44.7 mm (1.8 in) |
| 1937 | 57.2 mm (2.3 in) |
| 1938 | 22.3 mm (0.9 in) |
| 1939 | 18.8 mm (0.7 in) |
| 1940 | 33.2 mm (1.3 in) |
| 1941 | 40.4 mm (1.6 in) |
| 1942 | 38.9 mm (1.5 in) |
| 1943 | 20.9 mm (0.8 in) |
| 1944 | 37.2 mm (1.5 in) |
| 1945 | 34.2 mm (1.3 in) |
| 1947 | 28.5 mm (1.1 in) |
| 1948 | 52.6 mm (2.1 in) |
| 1949 | 21.1 mm (0.8 in) |
| 1950 | 41.6 mm (1.6 in) |
| 1951 | 36.3 mm (1.4 in) |
| 1952 | 29.7 mm (1.2 in) |
| 1953 | 27.7 mm (1.1 in) |
| 1954 | 38.1 mm (1.5 in) |
| 1955 | 22.6 mm (0.9 in) |
| 1956 | 22.4 mm (0.9 in) |
| 1957 | 29.5 mm (1.2 in) |
| 1958 | 25.2 mm (1.0 in) |
| 1959 | 29.5 mm (1.2 in) |
| 1960 | 34.4 mm (1.4 in) |
| 1961 | 28.7 mm (1.1 in) |
| 1962 | 33.6 mm (1.3 in) |
| 1963 | 33.0 mm (1.3 in) |
| 1964 | 37.4 mm (1.5 in) |
| 1965 | 40.7 mm (1.6 in) |
| 1966 | 28.7 mm (1.1 in) |
| 1967 | 17.1 mm (0.7 in) |
| 1968 | 39.7 mm (1.6 in) |
| 1969 | 29.2 mm (1.1 in) |
| 1970 | 25.9 mm (1.0 in) |
| 1971 | 40.2 mm (1.6 in) |
| 1972 | 60.4 mm (2.4 in) |
| 1973 | 49.0 mm (1.9 in) |
| 1974 | 23.6 mm (0.9 in) |
| 1975 | 30.9 mm (1.2 in) |
| 1976 | 22.4 mm (0.9 in) |
| 1977 | 31.5 mm (1.2 in) |
| 1978 | 29.5 mm (1.2 in) |
| 1979 | 19.8 mm (0.8 in) |
| 1980 | 51.4 mm (2.0 in) |
| 1981 | 24.7 mm (1.0 in) |
| 1982 | 27.0 mm (1.1 in) |
| 1983 | 31.7 mm (1.2 in) |
| 1984 | 41.1 mm (1.6 in) |
| 1985 | 28.2 mm (1.1 in) |
| 1986 | 35.1 mm (1.4 in) |
| 1987 | 44.7 mm (1.8 in) |
| 1988 | 23.6 mm (0.9 in) |
| 1989 | 30.0 mm (1.2 in) |
| 1990 | 32.3 mm (1.3 in) |
| 1991 | 26.7 mm (1.1 in) |
| 1992 | 30.6 mm (1.2 in) |
| 1993 | 37.6 mm (1.5 in) |
| 1994 | 21.7 mm (0.9 in) |
| 1995 | 36.1 mm (1.4 in) |
| 1996 | 65.5 mm (2.6 in) |
| 1997 | 30.5 mm (1.2 in) |
| 1998 | 33.3 mm (1.3 in) |
| 1999 | 22.6 mm (0.9 in) |
| 2000 | 28.1 mm (1.1 in) |
| 2001 | 32.8 mm (1.3 in) |
| 2002 | 31.8 mm (1.3 in) |
| 2003 | 34.6 mm (1.4 in) |
| 2004 | 19.3 mm (0.8 in) |
| 2005 | 32.3 mm (1.3 in) |
| 2006 | 37.8 mm (1.5 in) |
| 2007 | 21.7 mm (0.9 in) |
| 2008 | 25.2 mm (1.0 in) |
| 2009 | 16.6 mm (0.7 in) |
| 2010 | 36.3 mm (1.4 in) |
| 2011 | 34.0 mm (1.3 in) |
| 2012 | 73.6 mm (2.9 in) |
| 2013 | 32.2 mm (1.3 in) |
| 2014 | 27.2 mm (1.1 in) |
| 2015 | 40.4 mm (1.6 in) |
| 2016 | 44.5 mm (1.8 in) |
| 2017 | 32.7 mm (1.3 in) |
| 2018 | 27.9 mm (1.1 in) |
| 2019 | 34.6 mm (1.4 in) |
| 2020 | 36.1 mm (1.4 in) |
| 2021 | 34.3 mm (1.4 in) |
| 2022 | 36.1 mm (1.4 in) |
| 2023 | 43.7 mm (1.7 in) |
| 2024 | 27.9 mm (1.1 in) |
| 2025 | 20.3 mm (0.8 in) |
| 2026 | 25.5 mm (1.0 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1934 | 39 days |
| 1935 | 21 days |
| 1936 | 75 days |
| 1937 | 25 days |
| 1938 | 82 days |
| 1939 | 67 days |
| 1940 | 43 days |
| 1941 | 25 days |
| 1942 | 46 days |
| 1943 | 43 days |
| 1944 | 55 days |
| 1945 | 58 days |
| 1947 | 40 days |
| 1948 | 34 days |
| 1949 | 42 days |
| 1950 | 35 days |
| 1951 | 52 days |
| 1952 | 62 days |
| 1953 | 45 days |
| 1954 | 49 days |
| 1955 | 55 days |
| 1956 | 43 days |
| 1957 | 48 days |
| 1958 | 45 days |
| 1959 | 44 days |
| 1960 | 43 days |
| 1961 | 56 days |
| 1962 | 50 days |
| 1963 | 68 days |
| 1964 | 45 days |
| 1965 | 34 days |
| 1966 | 41 days |
| 1967 | 53 days |
| 1968 | 46 days |
| 1969 | 77 days |
| 1970 | 79 days |
| 1971 | 42 days |
| 1972 | 34 days |
| 1973 | 63 days |
| 1974 | 52 days |
| 1975 | 39 days |
| 1976 | 51 days |
| 1977 | 40 days |
| 1978 | 47 days |
| 1979 | 49 days |
| 1980 | 37 days |
| 1981 | 37 days |
| 1982 | 27 days |
| 1983 | 28 days |
| 1984 | 38 days |
| 1985 | 90 days |
| 1986 | 72 days |
| 1987 | 71 days |
| 1988 | 100 days |
| 1989 | 62 days |
| 1990 | 45 days |
| 1991 | 45 days |
| 1992 | 32 days |
| 1993 | 69 days |
| 1994 | 40 days |
| 1995 | 26 days |
| 1996 | 58 days |
| 1997 | 29 days |
| 1998 | 50 days |
| 1999 | 66 days |
| 2000 | 56 days |
| 2001 | 55 days |
| 2002 | 38 days |
| 2003 | 37 days |
| 2004 | 23 days |
| 2005 | 52 days |
| 2006 | 63 days |
| 2007 | 39 days |
| 2008 | 48 days |
| 2009 | 42 days |
| 2010 | 36 days |
| 2011 | 54 days |
| 2012 | 50 days |
| 2013 | 35 days |
| 2014 | 30 days |
| 2015 | 87 days |
| 2016 | 41 days |
| 2017 | 94 days |
| 2018 | 72 days |
| 2019 | 36 days |
| 2020 | 47 days |
| 2021 | 53 days |
| 2022 | 63 days |
| 2023 | 30 days |
| 2024 | 22 days |
| 2025 | 81 days |
| 2026 | 46 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
78 years with a frostAcross 78 years with a frost, the median last spring frost at Coulee Dam 1 SW falls on 22 April and the median first autumn frost on 19 October, which leaves a median of 181 days between them.
In 1989 to 2025 the median growing season was 180 days. That is 8 days fewer than in 1937 to 1969.
Fitted over all years, the growing season changes by -1.7 days per decade at this station.
| Measure | Median, all years | Earliest period (1937 to 1969) | Recent period (1989 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 22 April | 21 April | 24 April | 3 days later | +1.0 days per decade |
| First autumn frost | 19 October | 23 October | 19 October | 4 days earlier | -0.7 days per decade |
| Growing days | 181 days | 188 days | 180 days | 8 days fewer | -1.7 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.
Rainfall Return Levels
85 years, 1936 to 2025A day with at least 19.3 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 49.5 mm (1.9 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 19.3 mm (0.8 in) | |
| 5 years | 26.1 mm (1.0 in) | |
| 10 years | 31.1 mm (1.2 in) | |
| 25 years | 38.0 mm (1.5 in) | |
| 50 years | 43.5 mm (1.7 in) | |
| 100 years | 49.5 mm (1.9 in) | Longer than the 85 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, 85 years of values from 1936 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: 58.7 mm (2.3 in) in 1996; 40.6 mm (1.6 in) in 1984; 38.1 mm (1.5 in) in 2012.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Climate Twins
2011 to 2025 against 1961 to 1990Over 2011 to 2025, Coulee Dam 1 SW had a mean temperature of 10.4 C (50.7 F) and 278.4 mm (11.0 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Saltair Salt Plt (United States, 968 km away), Elberta (United States, 1,053 km away) and Nephi (United States, 1,081 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Saltair Salt Plt | United States | 968 km (601 mi) | 10.4 C (50.7 F) | 310.5 mm (12.2 in) | 0.64 |
| Elberta | United States | 1,053 km (654 mi) | 10.2 C (50.3 F) | 289.5 mm (11.4 in) | 0.69 |
| Nephi | United States | 1,081 km (672 mi) | 10.3 C (50.5 F) | 372.3 mm (14.7 in) | 0.78 |
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
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).