Bonneville Dam Threshold Days by Year (USC00350897)
17 fixed thresholds counted per year at Bonneville Dam (USC00350897): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Bonneville Dam Thresholds
- Bonneville Dam: days with 10 mm (0.39 in) or more of precipitation in 89 years, most in 1996 with 92.
- Bonneville Dam: days with 25 mm (0.98 in) or more of precipitation in 89 years, most in 1996 with 41.
- Bonneville Dam: days with a maximum temperature at or above 30 C (86 F) in 88 years, most in 2003 with 38.
- Bonneville Dam: days with a maximum temperature at or above 90 F (32.2 C) in 88 years, most in 2003 with 25.
- 17 fixed thresholds have at least one qualifying day at Bonneville Dam.
Days at or above 30 C (86 F)
88 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1938 | 25 | 25.5 |
| 1939 | 26 | 25.5 |
| 1940 | 25 | 16.5 |
| 1941 | 23 | 16.5 |
| 1942 | 21 | 16.5 |
| 1943 | 12 | 16.5 |
| 1944 | 18 | 16.5 |
| 1945 | 18 | 16.5 |
| 1946 | 16 | 16.5 |
| 1947 | 6 | 16.5 |
| 1948 | 13 | 16.5 |
| 1949 | 13 | 16.5 |
| 1950 | 18 | 16.9 |
| 1951 | 19 | 16.9 |
| 1952 | 22 | 16.9 |
| 1953 | 15 | 16.9 |
| 1955 | 10 | 16.9 |
| 1956 | 17 | 16.9 |
| 1957 | 7 | 16.9 |
| 1958 | 29 | 16.9 |
| 1959 | 15 | 16.9 |
| 1960 | 15 | 15.6 |
| 1961 | 25 | 15.6 |
| 1962 | 8 | 15.6 |
| 1963 | 12 | 15.6 |
| 1964 | 7 | 15.6 |
| 1965 | 11 | 15.6 |
| 1966 | 12 | 15.6 |
| 1967 | 34 | 15.6 |
| 1968 | 14 | 15.6 |
| 1969 | 18 | 15.6 |
| 1970 | 21 | 18.4 |
| 1971 | 19 | 18.4 |
| 1972 | 29 | 18.4 |
| 1973 | 17 | 18.4 |
| 1974 | 20 | 18.4 |
| 1975 | 16 | 18.4 |
| 1976 | 5 | 18.4 |
| 1977 | 23 | 18.4 |
| 1978 | 18 | 18.4 |
| 1979 | 16 | 18.4 |
| 1980 | 9 | 19.7 |
| 1981 | 18 | 19.7 |
| 1982 | 15 | 19.7 |
| 1983 | 7 | 19.7 |
| 1984 | 10 | 19.7 |
| 1985 | 27 | 19.7 |
| 1986 | 29 | 19.7 |
| 1987 | 37 | 19.7 |
| 1988 | 30 | 19.7 |
| 1989 | 15 | 19.7 |
| 1990 | 29 | 22.5 |
| 1991 | 24 | 22.5 |
| 1992 | 36 | 22.5 |
| 1993 | 15 | 22.5 |
| 1994 | 16 | 22.5 |
| 1995 | 12 | 22.5 |
| 1996 | 25 | 22.5 |
| 1997 | 21 | 22.5 |
| 1998 | 22 | 22.5 |
| 1999 | 25 | 22.5 |
| 2000 | 23 | 26.1 |
| 2001 | 20 | 26.1 |
| 2002 | 23 | 26.1 |
| 2003 | 38 | 26.1 |
| 2004 | 30 | 26.1 |
| 2005 | 22 | 26.1 |
| 2006 | 28 | 26.1 |
| 2007 | 24 | 26.1 |
| 2008 | 23 | 26.1 |
| 2009 | 30 | 26.1 |
| 2010 | 17 | 22.4 |
| 2011 | 8 | 22.4 |
| 2012 | 14 | 22.4 |
| 2013 | 18 | 22.4 |
| 2014 | 27 | 22.4 |
| 2015 | 37 | 22.4 |
| 2016 | 22 | 22.4 |
| 2017 | 33 | 22.4 |
| 2018 | 33 | 22.4 |
| 2019 | 15 | 22.4 |
| 2020 | 20 | 28.7 |
| 2021 | 30 | 28.7 |
| 2022 | 35 | 28.7 |
| 2023 | 36 | 28.7 |
| 2024 | 28 | 28.7 |
| 2025 | 28 | 28.7 |
| 2026 | 24 | 28.7 |
| Year | First date | Last date |
|---|---|---|
| 1938 | 1938-06-04 | 1938-09-18 |
| 1939 | 1939-05-13 | 1939-09-21 |
| 1940 | 1940-05-21 | 1940-08-29 |
| 1941 | 1941-05-10 | 1941-08-19 |
| 1942 | 1942-06-30 | 1942-09-25 |
| 1943 | 1943-06-29 | 1943-09-25 |
| 1944 | 1944-05-28 | 1944-09-11 |
| 1945 | 1945-06-17 | 1945-09-12 |
| 1946 | 1946-06-19 | 1946-09-10 |
| 1947 | 1947-05-25 | 1947-09-01 |
| 1948 | 1948-06-02 | 1948-09-13 |
| 1949 | 1949-06-06 | 1949-09-09 |
| 1950 | 1950-06-04 | 1950-09-22 |
| 1951 | 1951-06-21 | 1951-09-18 |
| 1952 | 1952-05-18 | 1952-10-03 |
| 1953 | 1953-05-06 | 1953-09-12 |
| 1955 | 1955-06-08 | 1955-09-07 |
| 1956 | 1956-05-17 | 1956-09-01 |
| 1957 | 1957-07-19 | 1957-09-24 |
| 1958 | 1958-06-06 | 1958-09-08 |
| 1959 | 1959-07-10 | 1959-08-15 |
| 1960 | 1960-07-06 | 1960-09-12 |
| 1961 | 1961-06-02 | 1961-08-23 |
| 1962 | 1962-07-22 | 1962-08-31 |
| 1963 | 1963-05-21 | 1963-09-28 |
| 1964 | 1964-06-01 | 1964-08-25 |
| 1965 | 1965-07-01 | 1965-08-18 |
| 1966 | 1966-06-16 | 1966-09-22 |
| 1967 | 1967-05-17 | 1967-09-28 |
| 1968 | 1968-06-25 | 1968-09-06 |
| 1969 | 1969-05-08 | 1969-09-11 |
| 1970 | 1970-05-16 | 1970-08-31 |
| 1971 | 1971-05-12 | 1971-08-29 |
| 1972 | 1972-05-13 | 1972-09-15 |
| 1973 | 1973-05-14 | 1973-09-11 |
| 1974 | 1974-06-29 | 1974-09-25 |
| 1975 | 1975-06-01 | 1975-09-14 |
| 1976 | 1976-06-19 | 1976-09-11 |
| 1977 | 1977-06-06 | 1977-09-13 |
| 1978 | 1978-06-03 | 1978-08-30 |
| 1979 | 1979-05-26 | 1979-09-19 |
| 1980 | 1980-07-21 | 1980-09-10 |
| 1981 | 1981-07-03 | 1981-09-16 |
| 1982 | 1982-05-25 | 1982-09-03 |
| 1983 | 1983-05-25 | 1983-08-14 |
| 1984 | 1984-06-24 | 1984-08-27 |
| 1985 | 1985-05-17 | 1985-08-27 |
| 1986 | 1986-05-31 | 1986-09-06 |
| 1987 | 1987-04-28 | 1987-10-02 |
| 1988 | 1988-05-12 | 1988-10-02 |
| 1989 | 1989-06-05 | 1989-09-25 |
| 1990 | 1990-06-22 | 1990-09-23 |
| 1991 | 1991-07-03 | 1991-09-26 |
| 1992 | 1992-05-05 | 1992-09-23 |
| 1993 | 1993-08-03 | 1993-10-04 |
| 1994 | 1994-06-28 | 1994-09-23 |
| 1995 | 1995-06-29 | 1995-09-15 |
| 1996 | 1996-06-03 | 1996-08-26 |
| 1997 | 1997-05-12 | 1997-09-25 |
| 1998 | 1998-04-30 | 1998-09-16 |
| 1999 | 1999-05-24 | 1999-09-23 |
| 2000 | 2000-06-04 | 2000-09-15 |
| 2001 | 2001-04-26 | 2001-09-23 |
| 2002 | 2002-06-13 | 2002-09-24 |
| 2003 | 2003-06-06 | 2003-09-29 |
| 2004 | 2004-04-27 | 2004-09-28 |
| 2005 | 2005-05-27 | 2005-09-02 |
| 2006 | 2006-05-16 | 2006-09-28 |
| 2007 | 2007-05-16 | 2007-09-12 |
| 2008 | 2008-05-16 | 2008-09-17 |
| 2009 | 2009-05-30 | 2009-09-24 |
| 2010 | 2010-07-07 | 2010-09-04 |
| 2011 | 2011-07-25 | 2011-09-12 |
| 2012 | 2012-05-15 | 2012-09-18 |
| 2013 | 2013-06-05 | 2013-09-12 |
| 2014 | 2014-05-03 | 2014-09-22 |
| 2015 | 2015-06-06 | 2015-09-12 |
| 2016 | 2016-05-03 | 2016-09-27 |
| 2017 | 2017-05-23 | 2017-09-12 |
| 2018 | 2018-05-15 | 2018-09-06 |
| 2019 | 2019-05-11 | 2019-09-06 |
| 2020 | 2020-05-29 | 2020-09-11 |
| 2021 | 2021-06-02 | 2021-09-09 |
| 2022 | 2022-06-26 | 2022-10-08 |
| 2023 | 2023-05-14 | 2023-09-16 |
| 2024 | 2024-05-11 | 2024-09-25 |
| 2025 | 2025-06-01 | 2025-09-05 |
| 2026 | 2026-05-04 | 2026-10-05 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 88 | 38 | 2003 | 24 |
| 35 C (95 F): Days | 79 | 9 | 2015 | 1 |
| 40 C (104 F): Days | 13 | 3 | 2021 | 1 |
| 90 F (32.2 C): Days | 88 | 25 | 2003 | 11 |
| 100 F (37.8 C): Days | 40 | 5 | 1938 | 3 |
| 110 F (43.3 C): Days | 1 | 1 | 2021 | 1 |
| 0 C (32 F): Ice days (max | 75 | 30 | 1985 | 1 |
| 0 C (32 F): Frost days (min | 85 | 70 | 1955 | 9 |
| -10 C (14 F): Days with min | 32 | 14 | 1950 | 5 |
| 20 C (68 F): Tropical nights (min | 27 | 4 | 1938 | 1 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 89 | 92 | 1996 | 29 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 89 | 41 | 1996 | 11 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 88 | 12 | 1996 | 1 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 16 | 2 | 1994 | 1 |
| 10 cm (3.9 in): Days with 10 cm or more snowfall | 44 | 11 | 1950 | 1 |
| 25 cm (9.8 in): Days with 25 cm or more snowfall | 11 | 3 | 1950 | 1 |
| 50 cm (19.7 in): Days with 50 cm or more snowfall | 1 | 1 | 1980 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1938.
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 2026-10-17 (17 October 2026). Threshold counts are computed by this site.
Data as of . Last revised (2026-10-17).