Diablo Dam Weather Records (USC00452157)
Record envelope, standing records and threshold days for Diablo Dam (USC00452157), Washington, United States, with 113 years of record.
Key Facts for Diablo Dam
- Diablo Dam (USC00452157) is a weather station in Washington, United States at 48.71 latitude and -121.14 longitude, 272 m (891 ft) above sea level.
- The station reports from 1914 to 2026, 113 years of record.
- 1,464 records set at Diablo Dam still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Diablo Dam tied a daily record low maximum temperature of 15.0 C (59.0 F) on 30 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, 48.71 latitude, -121.14 longitude.
- Elevation: 272 m (891 ft).
- Period of record: 1914 to 2026, 113 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
6 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 16.7 C (62.1 F) | -18.9 C (-2.0 F) | 8.9 C (48.0 F) | -4.4 C (24.1 F) |
| Feb | 17.2 C (63.0 F) | -17.8 C (0.0 F) | 11.1 C (52.0 F) | -6.7 C (19.9 F) |
| Mar | 24.4 C (75.9 F) | -12.8 C (9.0 F) | 15.6 C (60.1 F) | -2.2 C (28.0 F) |
| Apr | 32.2 C (90.0 F) | -4.4 C (24.1 F) | 29.4 C (84.9 F) | 0.6 C (33.1 F) |
| May | 39.4 C (102.9 F) | -2.2 C (28.0 F) | 31.1 C (88.0 F) | 1.7 C (35.1 F) |
| Jun | 43.3 C (109.9 F) | 0.6 C (33.1 F) | 34.4 C (93.9 F) | 5.0 C (41.0 F) |
| Jul | 41.1 C (106.0 F) | 3.3 C (37.9 F) | 38.3 C (100.9 F) | 9.4 C (48.9 F) |
| Aug | 41.1 C (106.0 F) | 2.8 C (37.0 F) | 33.9 C (93.0 F) | 8.9 C (48.0 F) |
| Sep | 38.3 C (100.9 F) | -0.6 C (30.9 F) | 28.3 C (82.9 F) | 5.0 C (41.0 F) |
| Oct | 30.6 C (87.1 F) | -7.8 C (18.0 F) | 25.0 C (77.0 F) | 3.3 C (37.9 F) |
| Nov | 18.3 C (64.9 F) | -15.0 C (5.0 F) | n/a | n/a |
| Dec | 17.2 C (63.0 F) | -18.9 C (-2.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1915 | 17 |
| 1916 | 26 |
| 1917 | 23 |
| 1918 | 15 |
| 1919 | 25 |
| 1920 | 20 |
| 1921 | 20 |
| 1922 | 10 |
| 1923 | 10 |
| 1924 | 25 |
| 1928 | 11 |
| 1929 | 16 |
| 1930 | 26 |
| 1931 | 8 |
| 1932 | 15 |
| 1934 | 19 |
| 1935 | 19 |
| 1936 | 35 |
| 1937 | 10 |
| 1938 | 14 |
| 1939 | 12 |
| 1940 | 27 |
| 1941 | 29 |
| 1942 | 23 |
| 1943 | 12 |
| 1944 | 11 |
| 1945 | 11 |
| 1946 | 6 |
| 1947 | 7 |
| 1948 | 5 |
| 1949 | 12 |
| 1950 | 35 |
| 1951 | 10 |
| 1952 | 20 |
| 1953 | 16 |
| 1954 | 13 |
| 1955 | 34 |
| 1956 | 17 |
| 1957 | 12 |
| 1958 | 28 |
| 1959 | 10 |
| 1960 | 9 |
| 1961 | 14 |
| 1962 | 16 |
| 1963 | 17 |
| 1964 | 7 |
| 1965 | 21 |
| 1966 | 7 |
| 1967 | 6 |
| 1968 | 5 |
| 1969 | 18 |
| 1970 | 11 |
| 1971 | 7 |
| 1972 | 15 |
| 1973 | 12 |
| 1974 | 10 |
| 1975 | 15 |
| 1976 | 6 |
| 1977 | 18 |
| 1978 | 7 |
| 1979 | 3 |
| 1980 | 10 |
| 1981 | 14 |
| 1982 | 11 |
| 1983 | 15 |
| 1984 | 17 |
| 1985 | 23 |
| 1986 | 10 |
| 1987 | 18 |
| 1988 | 14 |
| 1989 | 20 |
| 1990 | 13 |
| 1991 | 6 |
| 1992 | 27 |
| 1993 | 8 |
| 1994 | 10 |
| 1995 | 9 |
| 1996 | 14 |
| 1997 | 2 |
| 1998 | 13 |
| 1999 | 8 |
| 2000 | 3 |
| 2001 | 4 |
| 2002 | 10 |
| 2003 | 13 |
| 2004 | 12 |
| 2005 | 6 |
| 2006 | 9 |
| 2007 | 4 |
| 2008 | 8 |
| 2009 | 11 |
| 2010 | 11 |
| 2011 | 5 |
| 2012 | 7 |
| 2013 | 5 |
| 2014 | 9 |
| 2015 | 28 |
| 2016 | 16 |
| 2017 | 10 |
| 2018 | 7 |
| 2019 | 4 |
| 2020 | 9 |
| 2021 | 21 |
| 2022 | 12 |
| 2023 | 9 |
| 2024 | 6 |
| 2025 | 13 |
| 2026 | 12 |
All-Time Record Progression
5 new records| Date | Kind | Detail |
|---|---|---|
| 1950-01-03 | Record low maximum temperature | Record low maximum temperature -14.4 C (6.1 F) |
| 1950-01-14 | Record low maximum temperature | Record low maximum temperature -15.6 C (3.9 F) |
| 1950-01-29 | Record low minimum temperature | Record low minimum temperature -18.9 C (-2.0 F) |
| 1990-11-10 | Record daily precipitation | Record daily precipitation 185.9 mm (7.3 in) |
| 2021-06-28 | Record high maximum temperature | Record high maximum temperature 43.3 C (109.9 F) |
Wettest Day of Each Month
Nov: 185.9 mm (7.3 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 118.1 mm (4.6 in) | 10 January 1983 |
| Feb | 156.2 mm (6.1 in) | 10 February 1951 |
| Mar | 91.2 mm (3.6 in) | 12 March 2007 |
| Apr | 100.3 mm (3.9 in) | 6 April 1988 |
| May | 52.3 mm (2.1 in) | 13 May 1986 |
| Jun | 71.1 mm (2.8 in) | 2 June 1968 |
| Jul | 62.2 mm (2.4 in) | 12 July 1983 |
| Aug | 56.1 mm (2.2 in) | 25 August 2004 |
| Sep | 78.2 mm (3.1 in) | 18 September 2021 |
| Oct | 183.6 mm (7.2 in) | 17 October 2003 |
| Nov | 185.9 mm (7.3 in) | 10 November 1990 |
| Dec | 139.2 mm (5.5 in) | 3 December 1975 |
Period of Record Coverage
1914 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1914 | 8 | 2% | No |
| 1915 | 292 | 80% | No |
| 1916 | 364 | 99% | Yes |
| 1917 | 365 | 100% | Yes |
| 1918 | 335 | 92% | Yes |
| 1919 | 357 | 98% | Yes |
| 1920 | 317 | 87% | No |
| 1921 | 362 | 99% | Yes |
| 1922 | 362 | 99% | Yes |
| 1923 | 359 | 98% | Yes |
| 1924 | 358 | 98% | Yes |
| 1928 | 198 | 54% | No |
| 1929 | 361 | 99% | Yes |
| 1930 | 362 | 99% | Yes |
| 1931 | 333 | 91% | Yes |
| 1932 | 193 | 53% | No |
| 1934 | 333 | 91% | Yes |
| 1935 | 345 | 95% | Yes |
| 1936 | 365 | 100% | Yes |
| 1937 | 361 | 99% | Yes |
| 1938 | 364 | 100% | Yes |
| 1939 | 364 | 100% | Yes |
| 1940 | 366 | 100% | Yes |
| 1941 | 364 | 100% | Yes |
| 1942 | 365 | 100% | Yes |
| 1943 | 296 | 81% | No |
| 1944 | 363 | 99% | Yes |
| 1945 | 362 | 99% | Yes |
| 1946 | 364 | 100% | Yes |
| 1947 | 332 | 91% | Yes |
| 1948 | 363 | 99% | Yes |
| 1949 | 363 | 99% | Yes |
| 1950 | 363 | 99% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 366 | 100% | Yes |
| 1953 | 358 | 98% | Yes |
| 1954 | 338 | 93% | Yes |
| 1955 | 364 | 100% | Yes |
| 1956 | 366 | 100% | Yes |
| 1957 | 365 | 100% | Yes |
| 1958 | 365 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 341 | 93% | Yes |
| 1962 | 362 | 99% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 365 | 100% | Yes |
| 1965 | 334 | 92% | Yes |
| 1966 | 337 | 92% | Yes |
| 1967 | 363 | 99% | Yes |
| 1968 | 364 | 99% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 349 | 96% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 352 | 96% | Yes |
| 1978 | 364 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 365 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
| 1984 | 335 | 92% | Yes |
| 1985 | 303 | 83% | No |
| 1986 | 365 | 100% | Yes |
| 1987 | 334 | 92% | Yes |
| 1988 | 363 | 99% | Yes |
| 1989 | 365 | 100% | Yes |
| 1990 | 365 | 100% | Yes |
| 1991 | 365 | 100% | Yes |
| 1992 | 366 | 100% | Yes |
| 1993 | 364 | 100% | Yes |
| 1994 | 364 | 100% | Yes |
| 1995 | 365 | 100% | Yes |
| 1996 | 366 | 100% | Yes |
| 1997 | 303 | 83% | No |
| 1998 | 364 | 100% | Yes |
| 1999 | 365 | 100% | Yes |
| 2000 | 365 | 100% | Yes |
| 2001 | 364 | 100% | Yes |
| 2002 | 364 | 100% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 365 | 100% | Yes |
| 2005 | 365 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 364 | 100% | Yes |
| 2008 | 366 | 100% | Yes |
| 2009 | 272 | 75% | No |
| 2010 | 365 | 100% | Yes |
| 2011 | 364 | 100% | Yes |
| 2012 | 366 | 100% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 362 | 99% | Yes |
| 2016 | 365 | 100% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 365 | 100% | Yes |
| 2021 | 361 | 99% | Yes |
| 2022 | 362 | 99% | Yes |
| 2023 | 364 | 100% | Yes |
| 2024 | 365 | 100% | Yes |
| 2025 | 365 | 100% | Yes |
| 2026 | 284 | 78% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 30 August 2026 | Diablo Dam, US | daily low max (Tie, Provisional) | 15.0 C (59.0 F) | tie | 61 years | 7 of 100 (Routine) |
| 23 August 2026 | Diablo Dam, US | daily high min (Provisional) | 16.7 C (62.1 F) | 0.6 C (1.1 F) | 105 years | 42 of 100 (Notable) |
| 23 July 2026 | Diablo Dam, US | daily high max | 38.3 C (100.9 F) | 0.5 C (0.9 F) | 97 years | 39 of 100 (Notable) |
| 24 June 2026 | Diablo Dam, US | daily high max | 34.4 C (93.9 F) | 0.5 C (0.9 F) | 33 years | 20 of 100 (Routine) |
| 24 June 2026 | Diablo Dam, US | daily high min (Tie) | 13.9 C (57.0 F) | tie | 33 years | 5 of 100 (Routine) |
| 16 June 2026 | Diablo Dam, US | daily high min | 13.3 C (55.9 F) | 0.5 C (0.9 F) | 7 years | 14 of 100 (Routine) |
| 15 June 2026 | Diablo Dam, US | daily high max | 34.4 C (93.9 F) | 0.5 C (0.9 F) | 96 years | 38 of 100 (Notable) |
| 7 May 2026 | Diablo Dam, US | daily high min (Tie) | 11.1 C (52.0 F) | tie | 28 years | 4 of 100 (Routine) |
| 4 May 2026 | Diablo Dam, US | daily high max | 31.1 C (88.0 F) | 1.1 C (2.0 F) | 33 years | 21 of 100 (Routine) |
| 4 May 2026 | Diablo Dam, US | daily high min | 11.1 C (52.0 F) | 0.5 C (0.9 F) | 9 years | 13 of 100 (Routine) |
| 22 April 2026 | Diablo Dam, US | daily high min | 10.0 C (50.0 F) | 0.6 C (1.1 F) | 9 years | 14 of 100 (Routine) |
| 10 April 2026 | Diablo Dam, US | daily high max | 24.4 C (75.9 F) | 0.5 C (0.9 F) | 40 years | 22 of 100 (Routine) |
| 20 March 2026 | Diablo Dam, US | daily high min | 6.1 C (43.0 F) | 0.5 C (0.9 F) | 95 years | 40 of 100 (Notable) |
| 20 March 2026 | Diablo Dam, US | daily rain | 53.8 mm (2.1 in) | 1.7 mm (0.07 in) | 80 years | 35 of 100 (Notable) |
| 18 March 2026 | Diablo Dam, US | daily high min (Tie) | 4.4 C (39.9 F) | tie | 111 years | 10 of 100 (Routine) |
| 8 March 2026 | Diablo Dam, US | daily high min | 6.1 C (43.0 F) | 2.2 C (4.0 F) | 43 years | 31 of 100 (Routine) |
| 7 March 2026 | Diablo Dam, US | daily high min | 4.4 C (39.9 F) | 0.5 C (0.9 F) | 43 years | 24 of 100 (Routine) |
| 3 March 2026 | Diablo Dam, US | daily high max | 15.6 C (60.1 F) | 1.7 C (3.1 F) | 44 years | 26 of 100 (Routine) |
| 27 February 2026 | Diablo Dam, US | daily high min (Tie) | 5.0 C (41.0 F) | tie | 102 years | 10 of 100 (Routine) |
| 13 January 2026 | Diablo Dam, US | daily high min (Tie) | 4.4 C (39.9 F) | tie | 32 years | 4 of 100 (Routine) |
Climate Trend
88 complete years, 1916 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1916 | 7.8 C | -1.49 C |
| 1917 | 9.0 C | -0.28 C |
| 1919 | 8.4 C | -0.90 C |
| 1921 | 8.4 C | -0.87 C |
| 1922 | 8.2 C | -1.08 C |
| 1923 | 9.0 C | -0.24 C |
| 1924 | 9.2 C | -0.08 C |
| 1929 | 8.2 C | -1.06 C |
| 1930 | 8.7 C | -0.53 C |
| 1935 | 8.9 C | -0.39 C |
| 1936 | 8.4 C | -0.90 C |
| 1937 | 8.4 C | -0.88 C |
| 1938 | 9.2 C | -0.11 C |
| 1939 | 9.8 C | +0.55 C |
| 1940 | 10.2 C | +0.89 C |
| 1941 | 10.0 C | +0.77 C |
| 1942 | 9.7 C | +0.44 C |
| 1944 | 9.4 C | +0.18 C |
| 1945 | 9.0 C | -0.26 C |
| 1946 | 8.6 C | -0.66 C |
| 1948 | 8.2 C | -1.09 C |
| 1949 | 8.4 C | -0.87 C |
| 1950 | 8.2 C | -1.08 C |
| 1951 | 9.0 C | -0.27 C |
| 1952 | 9.6 C | +0.30 C |
| 1953 | 10.1 C | +0.86 C |
| 1955 | 7.6 C | -1.66 C |
| 1956 | 8.8 C | -0.43 C |
| 1957 | 9.2 C | -0.05 C |
| 1958 | 11.0 C | +1.74 C |
| 1959 | 9.0 C | -0.26 C |
| 1960 | 9.3 C | +0.01 C |
| 1962 | 9.3 C | +0.07 C |
| 1963 | 9.5 C | +0.21 C |
| 1964 | 8.4 C | -0.82 C |
| 1967 | 9.9 C | +0.67 C |
| 1968 | 9.2 C | -0.08 C |
| 1969 | 9.1 C | -0.17 C |
| 1970 | 9.3 C | 0.00 C |
| 1971 | 8.4 C | -0.91 C |
| 1972 | 8.3 C | -0.96 C |
| 1973 | 9.2 C | -0.10 C |
| 1974 | 9.4 C | +0.14 C |
| 1975 | 8.2 C | -1.08 C |
| 1976 | 9.1 C | -0.13 C |
| 1978 | 9.2 C | -0.05 C |
| 1979 | 9.4 C | +0.18 C |
| 1980 | 9.3 C | +0.01 C |
| 1981 | 9.8 C | +0.52 C |
| 1982 | 8.5 C | -0.74 C |
| 1983 | 9.3 C | +0.06 C |
| 1986 | 9.7 C | +0.39 C |
| 1988 | 9.6 C | +0.36 C |
| 1989 | 9.3 C | +0.02 C |
| 1990 | 9.5 C | +0.20 C |
| 1991 | 9.5 C | +0.21 C |
| 1992 | 10.5 C | +1.21 C |
| 1993 | 8.9 C | -0.39 C |
| 1994 | 9.8 C | +0.54 C |
| 1995 | 9.8 C | +0.53 C |
| 1996 | 8.5 C | -0.77 C |
| 1998 | 10.3 C | +1.05 C |
| 1999 | 9.0 C | -0.30 C |
| 2000 | 9.0 C | -0.29 C |
| 2001 | 9.3 C | 0.00 C |
| 2002 | 9.2 C | -0.08 C |
| 2003 | 10.0 C | +0.73 C |
| 2004 | 10.3 C | +1.05 C |
| 2005 | 9.8 C | +0.58 C |
| 2006 | 9.7 C | +0.47 C |
| 2007 | 9.1 C | -0.14 C |
| 2008 | 8.6 C | -0.71 C |
| 2010 | 9.6 C | +0.29 C |
| 2011 | 8.3 C | -1.00 C |
| 2012 | 9.3 C | +0.01 C |
| 2013 | 9.7 C | +0.45 C |
| 2014 | 9.9 C | +0.65 C |
| 2015 | 11.2 C | +1.92 C |
| 2016 | 10.3 C | +1.03 C |
| 2017 | 9.3 C | +0.08 C |
| 2018 | 9.9 C | +0.66 C |
| 2019 | 9.5 C | +0.23 C |
| 2020 | 9.6 C | +0.32 C |
| 2021 | 9.8 C | +0.50 C |
| 2022 | 9.2 C | -0.02 C |
| 2023 | 10.4 C | +1.15 C |
| 2024 | 10.3 C | +0.99 C |
| 2025 | 10.6 C | +1.32 C |
The annual mean temperature here has risen by 0.1 C (0.1 to 0.2) per decade over 1916 to 2025. In Fahrenheit: 0.2 F (0.1 to 0.3) per decade. The slope is a straight line fitted to 88 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 (0.1 to 0.2) per decade | 0.2 F (0.1 to 0.3) per decade | 1916 to 2025 | 88 | Rise |
| Mean daily maximum | 0.07 C (0.02 to 0.11) per decade | 0.12 F (0.03 to 0.21) per decade | 1916 to 2025 | 88 | Rise |
| Mean daily minimum | 0.2 C (0.1 to 0.2) per decade | 0.3 F (0.2 to 0.4) per decade | 1916 to 2025 | 88 | 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
1914 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 43.3 C (109.9 F) | 2021 | 36.7 C (98.1 F) | 109 |
| Coldest night (TNn) | -18.9 C (-2.0 F) | 1950 | -12.2 C (10.0 F) | 109 |
| Wettest day (Rx1day) | 185.9 mm (7.3 in) | 1990 | 80.3 mm (3.2 in) | 109 |
| Wettest five days (Rx5day) | 410.2 mm (16.1 in) | 2003 | 192.2 mm (7.6 in) | 109 |
| Longest dry spell (CDD) | 85 days | 2017 | 24 days | 109 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1914 | 4.4 C (39.9 F) |
| 1915 | 37.8 C (100.0 F) |
| 1916 | 36.7 C (98.1 F) |
| 1917 | 37.2 C (99.0 F) |
| 1918 | 41.1 C (106.0 F) |
| 1919 | 37.2 C (99.0 F) |
| 1920 | 37.2 C (99.0 F) |
| 1921 | 35.6 C (96.1 F) |
| 1922 | 36.1 C (97.0 F) |
| 1923 | 35.6 C (96.1 F) |
| 1924 | 36.7 C (98.1 F) |
| 1928 | 39.4 C (102.9 F) |
| 1929 | 33.9 C (93.0 F) |
| 1930 | 40.6 C (105.1 F) |
| 1931 | 35.6 C (96.1 F) |
| 1932 | 33.9 C (93.0 F) |
| 1934 | 36.1 C (97.0 F) |
| 1935 | 39.4 C (102.9 F) |
| 1936 | 34.4 C (93.9 F) |
| 1937 | 35.0 C (95.0 F) |
| 1938 | 41.1 C (106.0 F) |
| 1939 | 36.7 C (98.1 F) |
| 1940 | 36.7 C (98.1 F) |
| 1941 | 41.1 C (106.0 F) |
| 1942 | 39.4 C (102.9 F) |
| 1943 | 35.6 C (96.1 F) |
| 1944 | 39.4 C (102.9 F) |
| 1945 | 36.7 C (98.1 F) |
| 1946 | 35.6 C (96.1 F) |
| 1947 | 34.4 C (93.9 F) |
| 1948 | 34.4 C (93.9 F) |
| 1949 | 34.4 C (93.9 F) |
| 1950 | 34.4 C (93.9 F) |
| 1951 | 38.9 C (102.0 F) |
| 1952 | 38.3 C (100.9 F) |
| 1953 | 38.9 C (102.0 F) |
| 1954 | 30.6 C (87.1 F) |
| 1955 | 37.8 C (100.0 F) |
| 1956 | 36.7 C (98.1 F) |
| 1957 | 33.9 C (93.0 F) |
| 1958 | 38.9 C (102.0 F) |
| 1959 | 37.2 C (99.0 F) |
| 1960 | 37.8 C (100.0 F) |
| 1961 | 37.2 C (99.0 F) |
| 1962 | 33.3 C (91.9 F) |
| 1963 | 36.7 C (98.1 F) |
| 1964 | 33.3 C (91.9 F) |
| 1965 | 41.1 C (106.0 F) |
| 1966 | 36.1 C (97.0 F) |
| 1967 | 40.0 C (104.0 F) |
| 1968 | 35.0 C (95.0 F) |
| 1969 | 34.4 C (93.9 F) |
| 1970 | 38.3 C (100.9 F) |
| 1971 | 35.6 C (96.1 F) |
| 1972 | 35.6 C (96.1 F) |
| 1973 | 36.7 C (98.1 F) |
| 1974 | 37.2 C (99.0 F) |
| 1975 | 36.7 C (98.1 F) |
| 1976 | 33.9 C (93.0 F) |
| 1977 | 38.9 C (102.0 F) |
| 1978 | 40.6 C (105.1 F) |
| 1979 | 36.7 C (98.1 F) |
| 1980 | 35.6 C (96.1 F) |
| 1981 | 40.6 C (105.1 F) |
| 1982 | 37.8 C (100.0 F) |
| 1983 | 39.4 C (102.9 F) |
| 1984 | 34.4 C (93.9 F) |
| 1985 | 37.8 C (100.0 F) |
| 1986 | 38.3 C (100.9 F) |
| 1987 | 37.8 C (100.0 F) |
| 1988 | 38.3 C (100.9 F) |
| 1989 | 36.1 C (97.0 F) |
| 1990 | 37.8 C (100.0 F) |
| 1991 | 35.6 C (96.1 F) |
| 1992 | 36.7 C (98.1 F) |
| 1993 | 36.1 C (97.0 F) |
| 1994 | 37.8 C (100.0 F) |
| 1995 | 36.1 C (97.0 F) |
| 1996 | 37.8 C (100.0 F) |
| 1997 | 33.3 C (91.9 F) |
| 1998 | 38.9 C (102.0 F) |
| 1999 | 33.9 C (93.0 F) |
| 2000 | 33.9 C (93.0 F) |
| 2001 | 34.4 C (93.9 F) |
| 2002 | 36.7 C (98.1 F) |
| 2003 | 38.3 C (100.9 F) |
| 2004 | 37.8 C (100.0 F) |
| 2005 | 34.4 C (93.9 F) |
| 2006 | 40.0 C (104.0 F) |
| 2007 | 34.4 C (93.9 F) |
| 2008 | 38.3 C (100.9 F) |
| 2009 | 34.4 C (93.9 F) |
| 2010 | 36.7 C (98.1 F) |
| 2011 | 35.0 C (95.0 F) |
| 2012 | 36.1 C (97.0 F) |
| 2013 | 39.4 C (102.9 F) |
| 2014 | 36.1 C (97.0 F) |
| 2015 | 37.8 C (100.0 F) |
| 2016 | 37.8 C (100.0 F) |
| 2017 | 38.3 C (100.9 F) |
| 2018 | 38.3 C (100.9 F) |
| 2019 | 35.0 C (95.0 F) |
| 2020 | 40.0 C (104.0 F) |
| 2021 | 43.3 C (109.9 F) |
| 2022 | 39.4 C (102.9 F) |
| 2023 | 37.2 C (99.0 F) |
| 2024 | 36.7 C (98.1 F) |
| 2025 | 37.8 C (100.0 F) |
| 2026 | 38.3 C (100.9 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1914 | -5.6 C (21.9 F) |
| 1915 | -12.2 C (10.0 F) |
| 1916 | -16.7 C (1.9 F) |
| 1917 | -9.4 C (15.1 F) |
| 1918 | -12.2 C (10.0 F) |
| 1919 | -15.0 C (5.0 F) |
| 1920 | -9.4 C (15.1 F) |
| 1921 | -15.0 C (5.0 F) |
| 1922 | -16.1 C (3.0 F) |
| 1923 | -17.8 C (0.0 F) |
| 1924 | -17.8 C (0.0 F) |
| 1928 | -7.8 C (18.0 F) |
| 1929 | -18.3 C (-0.9 F) |
| 1930 | -16.1 C (3.0 F) |
| 1931 | -7.2 C (19.0 F) |
| 1932 | -16.7 C (1.9 F) |
| 1934 | -7.8 C (18.0 F) |
| 1935 | -13.3 C (8.1 F) |
| 1936 | -16.1 C (3.0 F) |
| 1937 | -16.1 C (3.0 F) |
| 1938 | -10.0 C (14.0 F) |
| 1939 | -12.8 C (9.0 F) |
| 1940 | -7.8 C (18.0 F) |
| 1941 | -10.0 C (14.0 F) |
| 1942 | -11.7 C (10.9 F) |
| 1943 | -15.6 C (3.9 F) |
| 1944 | -9.4 C (15.1 F) |
| 1945 | -9.4 C (15.1 F) |
| 1946 | -10.0 C (14.0 F) |
| 1947 | -15.6 C (3.9 F) |
| 1948 | -11.7 C (10.9 F) |
| 1949 | -16.1 C (3.0 F) |
| 1950 | -18.9 C (-2.0 F) |
| 1951 | -15.0 C (5.0 F) |
| 1952 | -16.7 C (1.9 F) |
| 1953 | -6.1 C (21.0 F) |
| 1954 | -15.0 C (5.0 F) |
| 1955 | -15.0 C (5.0 F) |
| 1956 | -13.3 C (8.1 F) |
| 1957 | -17.8 C (0.0 F) |
| 1958 | -7.2 C (19.0 F) |
| 1959 | -16.1 C (3.0 F) |
| 1960 | -8.9 C (16.0 F) |
| 1961 | -8.3 C (17.1 F) |
| 1962 | -16.1 C (3.0 F) |
| 1963 | -14.4 C (6.1 F) |
| 1964 | -15.6 C (3.9 F) |
| 1965 | -7.2 C (19.0 F) |
| 1966 | -9.4 C (15.1 F) |
| 1967 | -9.4 C (15.1 F) |
| 1968 | -11.1 C (12.0 F) |
| 1969 | -17.8 C (0.0 F) |
| 1970 | -10.6 C (12.9 F) |
| 1971 | -13.9 C (7.0 F) |
| 1972 | -16.1 C (3.0 F) |
| 1973 | -13.9 C (7.0 F) |
| 1974 | -10.0 C (14.0 F) |
| 1975 | -12.2 C (10.0 F) |
| 1976 | -10.0 C (14.0 F) |
| 1977 | -10.0 C (14.0 F) |
| 1978 | -17.2 C (1.0 F) |
| 1979 | -16.7 C (1.9 F) |
| 1980 | -15.6 C (3.9 F) |
| 1981 | -11.7 C (10.9 F) |
| 1982 | -15.6 C (3.9 F) |
| 1983 | -16.1 C (3.0 F) |
| 1984 | -8.3 C (17.1 F) |
| 1985 | -14.4 C (6.1 F) |
| 1986 | -10.6 C (12.9 F) |
| 1987 | -6.7 C (19.9 F) |
| 1988 | -11.1 C (12.0 F) |
| 1989 | -17.2 C (1.0 F) |
| 1990 | -18.9 C (-2.0 F) |
| 1991 | -10.6 C (12.9 F) |
| 1992 | -11.7 C (10.9 F) |
| 1993 | -13.9 C (7.0 F) |
| 1994 | -10.0 C (14.0 F) |
| 1995 | -10.0 C (14.0 F) |
| 1996 | -17.8 C (0.0 F) |
| 1997 | -12.8 C (9.0 F) |
| 1998 | -13.3 C (8.1 F) |
| 1999 | -5.6 C (21.9 F) |
| 2000 | -7.8 C (18.0 F) |
| 2001 | -6.7 C (19.9 F) |
| 2002 | -7.2 C (19.0 F) |
| 2003 | -8.9 C (16.0 F) |
| 2004 | -16.7 C (1.9 F) |
| 2005 | -10.0 C (14.0 F) |
| 2006 | -14.4 C (6.1 F) |
| 2007 | -11.1 C (12.0 F) |
| 2008 | -16.7 C (1.9 F) |
| 2009 | -11.7 C (10.9 F) |
| 2010 | -13.9 C (7.0 F) |
| 2011 | -12.8 C (9.0 F) |
| 2012 | -12.2 C (10.0 F) |
| 2013 | -11.1 C (12.0 F) |
| 2014 | -11.1 C (12.0 F) |
| 2015 | -6.7 C (19.9 F) |
| 2016 | -14.4 C (6.1 F) |
| 2017 | -14.4 C (6.1 F) |
| 2018 | -10.6 C (12.9 F) |
| 2019 | -11.7 C (10.9 F) |
| 2020 | -11.7 C (10.9 F) |
| 2021 | -13.9 C (7.0 F) |
| 2022 | -16.7 C (1.9 F) |
| 2023 | -9.4 C (15.1 F) |
| 2024 | -12.8 C (9.0 F) |
| 2025 | -11.7 C (10.9 F) |
| 2026 | -6.7 C (19.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1914 | 17.0 mm (0.7 in) |
| 1915 | 57.9 mm (2.3 in) |
| 1916 | 61.0 mm (2.4 in) |
| 1917 | 77.5 mm (3.1 in) |
| 1918 | 96.3 mm (3.8 in) |
| 1919 | 75.4 mm (3.0 in) |
| 1920 | 74.7 mm (2.9 in) |
| 1921 | 99.6 mm (3.9 in) |
| 1922 | 59.9 mm (2.4 in) |
| 1923 | 92.5 mm (3.6 in) |
| 1924 | 108.5 mm (4.3 in) |
| 1928 | 71.1 mm (2.8 in) |
| 1929 | 45.2 mm (1.8 in) |
| 1930 | 62.5 mm (2.5 in) |
| 1931 | 101.3 mm (4.0 in) |
| 1932 | 114.3 mm (4.5 in) |
| 1934 | 95.0 mm (3.7 in) |
| 1935 | 104.6 mm (4.1 in) |
| 1936 | 63.5 mm (2.5 in) |
| 1937 | 89.7 mm (3.5 in) |
| 1938 | 63.5 mm (2.5 in) |
| 1939 | 64.3 mm (2.5 in) |
| 1940 | 50.0 mm (2.0 in) |
| 1941 | 69.3 mm (2.7 in) |
| 1942 | 67.3 mm (2.6 in) |
| 1943 | 85.6 mm (3.4 in) |
| 1944 | 63.5 mm (2.5 in) |
| 1945 | 164.8 mm (6.5 in) |
| 1946 | 76.2 mm (3.0 in) |
| 1947 | 73.9 mm (2.9 in) |
| 1948 | 74.7 mm (2.9 in) |
| 1949 | 128.0 mm (5.0 in) |
| 1950 | 73.7 mm (2.9 in) |
| 1951 | 156.2 mm (6.1 in) |
| 1952 | 69.6 mm (2.7 in) |
| 1953 | 88.1 mm (3.5 in) |
| 1954 | 62.2 mm (2.4 in) |
| 1955 | 111.0 mm (4.4 in) |
| 1956 | 78.2 mm (3.1 in) |
| 1957 | 69.3 mm (2.7 in) |
| 1958 | 83.6 mm (3.3 in) |
| 1959 | 96.5 mm (3.8 in) |
| 1960 | 54.9 mm (2.2 in) |
| 1961 | 73.2 mm (2.9 in) |
| 1962 | 74.7 mm (2.9 in) |
| 1963 | 79.0 mm (3.1 in) |
| 1964 | 64.0 mm (2.5 in) |
| 1965 | 61.0 mm (2.4 in) |
| 1966 | 80.3 mm (3.2 in) |
| 1967 | 76.7 mm (3.0 in) |
| 1968 | 72.1 mm (2.8 in) |
| 1969 | 52.1 mm (2.1 in) |
| 1970 | 63.2 mm (2.5 in) |
| 1971 | 87.6 mm (3.4 in) |
| 1972 | 84.3 mm (3.3 in) |
| 1973 | 68.1 mm (2.7 in) |
| 1974 | 89.2 mm (3.5 in) |
| 1975 | 139.2 mm (5.5 in) |
| 1976 | 75.7 mm (3.0 in) |
| 1977 | 77.0 mm (3.0 in) |
| 1978 | 83.3 mm (3.3 in) |
| 1979 | 104.4 mm (4.1 in) |
| 1980 | 116.3 mm (4.6 in) |
| 1981 | 63.0 mm (2.5 in) |
| 1982 | 87.9 mm (3.5 in) |
| 1983 | 118.1 mm (4.6 in) |
| 1984 | 88.9 mm (3.5 in) |
| 1985 | 77.5 mm (3.1 in) |
| 1986 | 100.6 mm (4.0 in) |
| 1987 | 79.0 mm (3.1 in) |
| 1988 | 100.3 mm (3.9 in) |
| 1989 | 108.7 mm (4.3 in) |
| 1990 | 185.9 mm (7.3 in) |
| 1991 | 77.7 mm (3.1 in) |
| 1992 | 53.3 mm (2.1 in) |
| 1993 | 94.5 mm (3.7 in) |
| 1994 | 88.1 mm (3.5 in) |
| 1995 | 160.0 mm (6.3 in) |
| 1996 | 66.0 mm (2.6 in) |
| 1997 | 79.2 mm (3.1 in) |
| 1998 | 76.2 mm (3.0 in) |
| 1999 | 86.6 mm (3.4 in) |
| 2000 | 69.1 mm (2.7 in) |
| 2001 | 71.6 mm (2.8 in) |
| 2002 | 154.9 mm (6.1 in) |
| 2003 | 183.6 mm (7.2 in) |
| 2004 | 104.6 mm (4.1 in) |
| 2005 | 89.7 mm (3.5 in) |
| 2006 | 103.9 mm (4.1 in) |
| 2007 | 91.2 mm (3.6 in) |
| 2008 | 73.4 mm (2.9 in) |
| 2009 | 104.6 mm (4.1 in) |
| 2010 | 82.0 mm (3.2 in) |
| 2011 | 77.5 mm (3.1 in) |
| 2012 | 70.4 mm (2.8 in) |
| 2013 | 99.8 mm (3.9 in) |
| 2014 | 91.9 mm (3.6 in) |
| 2015 | 94.0 mm (3.7 in) |
| 2016 | 88.4 mm (3.5 in) |
| 2017 | 92.7 mm (3.6 in) |
| 2018 | 68.3 mm (2.7 in) |
| 2019 | 103.9 mm (4.1 in) |
| 2020 | 96.0 mm (3.8 in) |
| 2021 | 122.4 mm (4.8 in) |
| 2022 | 90.2 mm (3.6 in) |
| 2023 | 102.9 mm (4.1 in) |
| 2024 | 71.1 mm (2.8 in) |
| 2025 | 119.9 mm (4.7 in) |
| 2026 | 61.5 mm (2.4 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1914 | 59.2 mm (2.3 in) |
| 1915 | 122.4 mm (4.8 in) |
| 1916 | 175.2 mm (6.9 in) |
| 1917 | 241.3 mm (9.5 in) |
| 1918 | 230.2 mm (9.1 in) |
| 1919 | 178.1 mm (7.0 in) |
| 1920 | 239.3 mm (9.4 in) |
| 1921 | 270.1 mm (10.6 in) |
| 1922 | 154.9 mm (6.1 in) |
| 1923 | 189.3 mm (7.5 in) |
| 1924 | 273.2 mm (10.8 in) |
| 1928 | 168.8 mm (6.6 in) |
| 1929 | 148.9 mm (5.9 in) |
| 1930 | 145.4 mm (5.7 in) |
| 1931 | 179.2 mm (7.1 in) |
| 1932 | 292.6 mm (11.5 in) |
| 1934 | 185.7 mm (7.3 in) |
| 1935 | 273.8 mm (10.8 in) |
| 1936 | 168.9 mm (6.6 in) |
| 1937 | 214.4 mm (8.4 in) |
| 1938 | 179.3 mm (7.1 in) |
| 1939 | 238.3 mm (9.4 in) |
| 1940 | 138.5 mm (5.5 in) |
| 1941 | 125.9 mm (5.0 in) |
| 1942 | 118.4 mm (4.7 in) |
| 1943 | 160.6 mm (6.3 in) |
| 1944 | 120.9 mm (4.8 in) |
| 1945 | 263.3 mm (10.4 in) |
| 1946 | 216.3 mm (8.5 in) |
| 1947 | 181.9 mm (7.2 in) |
| 1948 | 203.5 mm (8.0 in) |
| 1949 | 258.3 mm (10.2 in) |
| 1950 | 178.1 mm (7.0 in) |
| 1951 | 389.4 mm (15.3 in) |
| 1952 | 134.9 mm (5.3 in) |
| 1953 | 185.3 mm (7.3 in) |
| 1954 | 196.5 mm (7.7 in) |
| 1955 | 228.6 mm (9.0 in) |
| 1956 | 187.2 mm (7.4 in) |
| 1957 | 203.2 mm (8.0 in) |
| 1958 | 167.0 mm (6.6 in) |
| 1959 | 217.6 mm (8.6 in) |
| 1960 | 138.7 mm (5.5 in) |
| 1961 | 185.4 mm (7.3 in) |
| 1962 | 158.5 mm (6.2 in) |
| 1963 | 186.4 mm (7.3 in) |
| 1964 | 132.1 mm (5.2 in) |
| 1965 | 140.2 mm (5.5 in) |
| 1966 | 201.9 mm (7.9 in) |
| 1967 | 211.5 mm (8.3 in) |
| 1968 | 150.5 mm (5.9 in) |
| 1969 | 142.2 mm (5.6 in) |
| 1970 | 146.3 mm (5.8 in) |
| 1971 | 181.0 mm (7.1 in) |
| 1972 | 215.9 mm (8.5 in) |
| 1973 | 136.9 mm (5.4 in) |
| 1974 | 284.2 mm (11.2 in) |
| 1975 | 404.1 mm (15.9 in) |
| 1976 | 134.3 mm (5.3 in) |
| 1977 | 208.0 mm (8.2 in) |
| 1978 | 155.5 mm (6.1 in) |
| 1979 | 313.4 mm (12.3 in) |
| 1980 | 236.4 mm (9.3 in) |
| 1981 | 200.4 mm (7.9 in) |
| 1982 | 204.2 mm (8.0 in) |
| 1983 | 252.8 mm (10.0 in) |
| 1984 | 226.0 mm (8.9 in) |
| 1985 | 193.4 mm (7.6 in) |
| 1986 | 251.9 mm (9.9 in) |
| 1987 | 146.3 mm (5.8 in) |
| 1988 | 210.1 mm (8.3 in) |
| 1989 | 274.3 mm (10.8 in) |
| 1990 | 392.9 mm (15.5 in) |
| 1991 | 175.0 mm (6.9 in) |
| 1992 | 124.5 mm (4.9 in) |
| 1993 | 128.6 mm (5.1 in) |
| 1994 | 190.2 mm (7.5 in) |
| 1995 | 289.8 mm (11.4 in) |
| 1996 | 223.5 mm (8.8 in) |
| 1997 | 185.4 mm (7.3 in) |
| 1998 | 234.4 mm (9.2 in) |
| 1999 | 206.0 mm (8.1 in) |
| 2000 | 112.6 mm (4.4 in) |
| 2001 | 219.8 mm (8.7 in) |
| 2002 | 237.9 mm (9.4 in) |
| 2003 | 410.2 mm (16.1 in) |
| 2004 | 202.2 mm (8.0 in) |
| 2005 | 236.4 mm (9.3 in) |
| 2006 | 346.2 mm (13.6 in) |
| 2007 | 179.8 mm (7.1 in) |
| 2008 | 153.3 mm (6.0 in) |
| 2009 | 250.2 mm (9.9 in) |
| 2010 | 232.6 mm (9.2 in) |
| 2011 | 249.0 mm (9.8 in) |
| 2012 | 164.0 mm (6.5 in) |
| 2013 | 161.8 mm (6.4 in) |
| 2014 | 276.0 mm (10.9 in) |
| 2015 | 265.2 mm (10.4 in) |
| 2016 | 152.8 mm (6.0 in) |
| 2017 | 208.6 mm (8.2 in) |
| 2018 | 155.8 mm (6.1 in) |
| 2019 | 187.9 mm (7.4 in) |
| 2020 | 190.7 mm (7.5 in) |
| 2021 | 274.8 mm (10.8 in) |
| 2022 | 137.1 mm (5.4 in) |
| 2023 | 220.2 mm (8.7 in) |
| 2024 | 132.3 mm (5.2 in) |
| 2025 | 288.5 mm (11.4 in) |
| 2026 | 192.2 mm (7.6 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1914 | 1 day |
| 1915 | 19 days |
| 1916 | 22 days |
| 1917 | 23 days |
| 1918 | 42 days |
| 1919 | 26 days |
| 1920 | 26 days |
| 1921 | 18 days |
| 1922 | 41 days |
| 1923 | 30 days |
| 1924 | 17 days |
| 1928 | 30 days |
| 1929 | 22 days |
| 1930 | 31 days |
| 1931 | 36 days |
| 1932 | 26 days |
| 1934 | 30 days |
| 1935 | 25 days |
| 1936 | 44 days |
| 1937 | 40 days |
| 1938 | 28 days |
| 1939 | 24 days |
| 1940 | 43 days |
| 1941 | 16 days |
| 1942 | 27 days |
| 1943 | 21 days |
| 1944 | 16 days |
| 1945 | 20 days |
| 1946 | 18 days |
| 1947 | 14 days |
| 1948 | 14 days |
| 1949 | 17 days |
| 1950 | 30 days |
| 1951 | 48 days |
| 1952 | 38 days |
| 1953 | 14 days |
| 1954 | 22 days |
| 1955 | 25 days |
| 1956 | 26 days |
| 1957 | 20 days |
| 1958 | 29 days |
| 1959 | 17 days |
| 1960 | 39 days |
| 1961 | 20 days |
| 1962 | 16 days |
| 1963 | 26 days |
| 1964 | 10 days |
| 1965 | 21 days |
| 1966 | 16 days |
| 1967 | 25 days |
| 1968 | 24 days |
| 1969 | 23 days |
| 1970 | 31 days |
| 1971 | 42 days |
| 1972 | 32 days |
| 1973 | 26 days |
| 1974 | 25 days |
| 1975 | 15 days |
| 1976 | 17 days |
| 1977 | 16 days |
| 1978 | 16 days |
| 1979 | 32 days |
| 1980 | 17 days |
| 1981 | 40 days |
| 1982 | 24 days |
| 1983 | 25 days |
| 1984 | 31 days |
| 1985 | 31 days |
| 1986 | 54 days |
| 1987 | 18 days |
| 1988 | 17 days |
| 1989 | 23 days |
| 1990 | 22 days |
| 1991 | 32 days |
| 1992 | 15 days |
| 1993 | 19 days |
| 1994 | 19 days |
| 1995 | 28 days |
| 1996 | 14 days |
| 1997 | 26 days |
| 1998 | 35 days |
| 1999 | 16 days |
| 2000 | 20 days |
| 2001 | 20 days |
| 2002 | 27 days |
| 2003 | 27 days |
| 2004 | 24 days |
| 2005 | 24 days |
| 2006 | 22 days |
| 2007 | 18 days |
| 2008 | 23 days |
| 2009 | 15 days |
| 2010 | 18 days |
| 2011 | 27 days |
| 2012 | 35 days |
| 2013 | 17 days |
| 2014 | 19 days |
| 2015 | 26 days |
| 2016 | 22 days |
| 2017 | 85 days |
| 2018 | 28 days |
| 2019 | 17 days |
| 2020 | 24 days |
| 2021 | 23 days |
| 2022 | 37 days |
| 2023 | 19 days |
| 2024 | 29 days |
| 2025 | 29 days |
| 2026 | 29 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
88 years with a frostAcross 88 years with a frost, the median last spring frost at Diablo Dam falls on 16 April and the median first autumn frost on 31 October, which leaves a median of 195 days between them.
In 1994 to 2025 the median growing season was 199 days. That is 10 days more than in 1916 to 1958.
Fitted over all years, the growing season changes by +2.3 days per decade at this station.
| Measure | Median, all years | Earliest period (1916 to 1958) | Recent period (1994 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 16 April | 18 April | 14 April | 4 days earlier | -1.1 days per decade |
| First autumn frost | 31 October | 28 October | 31 October | 3 days later | +1.2 days per decade |
| Growing days | 195 days | 189 days | 199 days | 10 days more | +2.3 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
100 years, 1915 to 2025A day with at least 82.2 mm (3.2 in) of rain is expected about once in 2 years. A day with at least 185.5 mm (7.3 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 82.2 mm (3.2 in) | |
| 5 years | 104.9 mm (4.1 in) | |
| 10 years | 121.8 mm (4.8 in) | |
| 25 years | 145.4 mm (5.7 in) | |
| 50 years | 164.7 mm (6.5 in) | |
| 100 years | 185.5 mm (7.3 in) |
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 100 years of values from 1915 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: 185.9 mm (7.3 in) in 1990; 183.6 mm (7.2 in) in 2003; 164.8 mm (6.5 in) in 1945.
Station Changes
2 suspected2 changes were suspected in the annual mean temperature of Diablo Dam, at 1951 and 1959. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1951 ran 0.4 C (0.7 F) higher than in the years before (possible change).
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1959 ran 0.2 C (0.3 F) lower than in the years before (likely change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 1951 | +0.4 | +0.7 | possible | 5 |
| 1959 | -0.2 | -0.3 | likely | 5 |
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Climate Twins
2011 to 2025 against 1961 to 1990Over 2011 to 2025, Diablo Dam had a mean temperature of 9.8 C (49.7 F) and 1,962.0 mm (77.2 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Belknap Springs 8 N (United States, 497 km away), Three Lynx (United States, 405 km away) and Krasnaja Poljana (Russia, 9,590 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Belknap Springs 8 N | United States | 497 km (309 mi) | 8.9 C (48.0 F) | 1,859.5 mm (73.2 in) | 1.31 |
| Three Lynx | United States | 405 km (252 mi) | 9.8 C (49.7 F) | 1,837.8 mm (72.4 in) | 1.48 |
| Krasnaja Poljana | Russia | 9,590 km (5,959 mi) | 11.0 C (51.8 F) | 1,948.6 mm (76.7 in) | 1.50 |
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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-14).