Iwamizawa Threshold Days by Year
14 fixed thresholds counted per year at Iwamizawa (JA000047413): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Iwamizawa Thresholds
- Iwamizawa: days with a maximum temperature at or below 0 C (32 F) in 66 years, most in 1984 with 94.
- Iwamizawa: days with a maximum temperature at or above 30 C (86 F) in 61 years, most in 2021 with 23.
- Iwamizawa: days with 10 mm (0.39 in) or more of precipitation in 54 years, most in 1974 with 51.
- Iwamizawa: days with 25 mm (0.98 in) or more of precipitation in 53 years, most in 2011 with 16.
- 14 fixed thresholds have at least one qualifying day at Iwamizawa.
Days at or above 30 C (86 F)
61 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1951 | 13 | 7.5 |
| 1952 | 4 | 7.5 |
| 1953 | 4 | 7.5 |
| 1955 | 12 | 7.5 |
| 1958 | 6 | 7.5 |
| 1959 | 6 | 7.5 |
| 1960 | 8 | 4.9 |
| 1961 | 4 | 4.9 |
| 1962 | 2 | 4.9 |
| 1963 | 4 | 4.9 |
| 1964 | 2 | 4.9 |
| 1965 | 3 | 4.9 |
| 1966 | 4 | 4.9 |
| 1967 | 9 | 4.9 |
| 1968 | 9 | 4.9 |
| 1969 | 4 | 4.9 |
| 1970 | 8 | 7.8 |
| 1971 | 6 | 7.8 |
| 1972 | 6 | 7.8 |
| 1973 | 18 | 7.8 |
| 1974 | 7 | 7.8 |
| 1975 | 4 | 7.8 |
| 1976 | 5 | 7.8 |
| 1977 | 6 | 7.8 |
| 1978 | 13 | 7.8 |
| 1979 | 5 | 7.8 |
| 1980 | 1 | 7.4 |
| 1981 | 6 | 7.4 |
| 1982 | 5 | 7.4 |
| 1983 | 7 | 7.4 |
| 1984 | 20 | 7.4 |
| 1985 | 13 | 7.4 |
| 1986 | 6 | 7.4 |
| 1987 | 3 | 7.4 |
| 1988 | 5 | 7.4 |
| 1989 | 8 | 7.4 |
| 1992 | 1 | 4.6 |
| 1994 | 17 | 4.6 |
| 1995 | 2 | 4.6 |
| 1996 | 1 | 4.6 |
| 1998 | 2 | 4.6 |
| 2000 | 10 | 5.3 |
| 2002 | 1 | 5.3 |
| 2006 | 12 | 5.3 |
| 2007 | 4 | 5.3 |
| 2008 | 2 | 5.3 |
| 2009 | 3 | 5.3 |
| 2010 | 16 | 10 |
| 2011 | 8 | 10 |
| 2012 | 17 | 10 |
| 2013 | 6 | 10 |
| 2014 | 10 | 10 |
| 2015 | 5 | 10 |
| 2016 | 8 | 10 |
| 2017 | 9 | 10 |
| 2018 | 6 | 10 |
| 2019 | 15 | 10 |
| 2021 | 23 | 14 |
| 2022 | 6 | 14 |
| 2025 | 22 | 14 |
| 2026 | 5 | 14 |
| Year | First date | Last date |
|---|---|---|
| 1951 | 1951-07-29 | 1951-08-24 |
| 1952 | 1952-07-23 | 1952-08-09 |
| 1953 | 1953-07-29 | 1953-08-12 |
| 1955 | 1955-07-14 | 1955-08-27 |
| 1958 | 1958-06-27 | 1958-08-12 |
| 1959 | 1959-08-14 | 1959-08-21 |
| 1960 | 1960-07-19 | 1960-08-10 |
| 1961 | 1961-07-29 | 1961-08-14 |
| 1962 | 1962-08-15 | 1962-08-16 |
| 1963 | 1963-07-12 | 1963-08-11 |
| 1964 | 1964-06-26 | 1964-08-20 |
| 1965 | 1965-08-19 | 1965-08-29 |
| 1966 | 1966-06-22 | 1966-08-31 |
| 1967 | 1967-07-16 | 1967-08-07 |
| 1968 | 1968-07-21 | 1968-08-06 |
| 1969 | 1969-07-18 | 1969-07-25 |
| 1970 | 1970-07-22 | 1970-08-22 |
| 1971 | 1971-07-30 | 1971-08-06 |
| 1972 | 1972-07-20 | 1972-08-13 |
| 1973 | 1973-07-15 | 1973-08-17 |
| 1974 | 1974-07-23 | 1974-08-19 |
| 1975 | 1975-08-01 | 1975-08-18 |
| 1976 | 1976-07-23 | 1976-07-27 |
| 1977 | 1977-07-24 | 1977-07-31 |
| 1978 | 1978-06-26 | 1978-08-20 |
| 1979 | 1979-07-31 | 1979-08-16 |
| 1980 | 1980-06-07 | 1980-06-07 |
| 1981 | 1981-07-18 | 1981-08-03 |
| 1982 | 1982-07-07 | 1982-08-04 |
| 1983 | 1983-08-05 | 1983-08-17 |
| 1984 | 1984-07-21 | 1984-08-21 |
| 1985 | 1985-07-26 | 1985-08-17 |
| 1986 | 1986-07-30 | 1986-08-17 |
| 1987 | 1987-06-26 | 1987-08-31 |
| 1988 | 1988-08-02 | 1988-08-09 |
| 1989 | 1989-07-26 | 1989-08-22 |
| 1992 | 1992-07-07 | 1992-07-07 |
| 1994 | 1994-07-18 | 1994-09-06 |
| 1995 | 1995-07-26 | 1995-07-27 |
| 1996 | 1996-08-14 | 1996-08-14 |
| 1998 | 1998-07-26 | 1998-07-27 |
| 2000 | 2000-07-11 | 2000-08-18 |
| 2002 | 2002-07-26 | 2002-07-26 |
| 2006 | 2006-07-14 | 2006-08-26 |
| 2007 | 2007-08-12 | 2007-08-15 |
| 2008 | 2008-07-06 | 2008-08-05 |
| 2009 | 2009-07-07 | 2009-08-11 |
| 2010 | 2010-06-26 | 2010-09-02 |
| 2011 | 2011-07-28 | 2011-09-01 |
| 2012 | 2012-07-18 | 2012-09-18 |
| 2013 | 2013-07-07 | 2013-08-19 |
| 2014 | 2014-06-03 | 2014-08-04 |
| 2015 | 2015-07-11 | 2015-08-13 |
| 2016 | 2016-08-02 | 2016-09-02 |
| 2017 | 2017-07-07 | 2017-07-30 |
| 2018 | 2018-06-04 | 2018-08-02 |
| 2019 | 2019-05-26 | 2019-09-09 |
| 2021 | 2021-06-27 | 2021-08-08 |
| 2022 | 2022-07-03 | 2022-09-09 |
| 2025 | 2025-06-19 | 2025-08-16 |
| 2026 | 2026-07-16 | 2026-08-22 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 61 | 23 | 2021 | 5 |
| 35 C (95 F): Days | 1 | 4 | 2021 | 4 |
| 90 F (32.2 C): Days | 32 | 17 | 2021 | 8 |
| 0 C (32 F): Ice days (max | 66 | 94 | 1984 | 37 |
| 0 C (32 F): Frost days (min | 41 | 170 | 1952 | 76 |
| -10 C (14 F): Days with min | 41 | 77 | 1952 | 16 |
| -20 C (-4 F): Days with min | 24 | 6 | 1952 | 3 |
| 20 C (68 F): Tropical nights (min | 40 | 43 | 2025 | 24 |
| 25 C (77 F): Days with min | 1 | 1 | 2025 | 1 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 54 | 51 | 1974 | 28 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 53 | 16 | 2011 | 24 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 38 | 5 | 1981 | 18 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 10 | 4 | 1981 | 9 |
| 200 mm (7.87 in): Days with 200 mm or more rain | 2 | 1 | 1981 | 2 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1951.
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).