Prosser Threshold Days by Year (USC00456768)

16 fixed thresholds counted per year at Prosser (USC00456768): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Prosser Thresholds

Prosser: days with a maximum temperature at or above 30 C (86 F) in 79 years, most in 2025 with 88.
Prosser: days with a maximum temperature at or above 35 C (95 F) in 79 years, most in 2021 with 43.
Prosser: days with a maximum temperature at or above 90 F (32.2 C) in 79 years, most in 1958 with 64.
Prosser: days with a maximum temperature at or below 0 C (32 F) in 78 years, most in 1985 with 66.
16 fixed thresholds have at least one qualifying day at Prosser.

Days at or above 30 C (86 F)

79 years with a qualifying day

Days per year at Prosser with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 88 in 2025.

Days at or above 30 C (86 F) per year at Prosser
Year	Days	Decade average
1931	71	64.2
1933	50	64.2
1937	60	64.2
1938	80	64.2
1939	60	64.2
1940	61	52.7
1941	48	52.7
1942	57	52.7
1943	53	52.7
1944	56	52.7
1945	60	52.7
1946	43	52.7
1947	54	52.7
1948	42	52.7
1949	53	52.7
1950	53	51.1
1951	58	51.1
1952	63	51.1
1953	41	51.1
1954	32	51.1
1955	45	51.1
1956	59	51.1
1957	40	51.1
1958	78	51.1
1959	42	51.1
1960	59	52.6
1961	66	52.6
1962	43	52.6
1963	43	52.6
1964	30	52.6
1965	44	52.6
1966	53	52.6
1967	85	52.6
1968	43	52.6
1969	60	52.6
1970	57	49.9
1971	44	49.9
1972	52	49.9
1973	56	49.9
1974	52	49.9
1975	46	49.9
1976	35	49.9
1977	56	49.9
1978	40	49.9
1979	61	49.9
1980	30	51.4
1981	54	51.4
1982	51	51.4
1983	38	51.4
1984	51	51.4
1985	56	51.4
1987	71	51.4
1988	60	51.4
1990	60	56.8
1991	50	56.8
1993	39	56.8
1997	67	56.8
1999	68	56.8
2000	70	69.9
2001	76	69.9
2002	69	69.9
2003	80	69.9
2004	63	69.9
2005	63	69.9
2006	74	69.9
2007	64	69.9
2011	55	65.3
2013	80	65.3
2016	59	65.3
2017	69	65.3
2018	65	65.3
2019	64	65.3
2020	65	74.9
2021	71	74.9
2022	68	74.9
2023	78	74.9
2024	67	74.9
2025	88	74.9
2026	87	74.9

For each year, a bar from the first to the last day at Prosser meeting 30 C (86 F).

First to last qualifying date each year at Prosser
Year	First date	Last date
1931	1931-04-29	1931-09-05
1933	1933-06-02	1933-09-04
1937	1937-05-02	1937-09-16
1938	1938-05-22	1938-09-22
1939	1939-04-28	1939-09-23
1940	1940-05-08	1940-09-11
1941	1941-05-11	1941-08-22
1942	1942-04-20	1942-09-27
1943	1943-04-14	1943-10-08
1944	1944-05-14	1944-09-25
1945	1945-05-03	1945-09-14
1946	1946-04-25	1946-09-11
1947	1947-04-13	1947-09-24
1948	1948-05-26	1948-09-14
1949	1949-05-09	1949-09-28
1950	1950-05-13	1950-09-24
1951	1951-05-23	1951-09-20
1952	1952-04-19	1952-09-27
1953	1953-07-03	1953-09-16
1954	1954-05-18	1954-09-27
1955	1955-06-07	1955-09-12
1956	1956-05-17	1956-09-20
1957	1957-04-30	1957-09-16
1958	1958-05-17	1958-10-04
1959	1959-05-14	1959-09-14
1960	1960-05-11	1960-09-29
1961	1961-05-21	1961-08-31
1962	1962-06-09	1962-09-22
1963	1963-05-21	1963-09-29
1964	1964-06-24	1964-09-25
1965	1965-05-29	1965-09-02
1966	1966-05-04	1966-09-23
1967	1967-05-17	1967-09-29
1968	1968-04-30	1968-09-10
1969	1969-05-09	1969-09-13
1970	1970-05-26	1970-09-01
1971	1971-05-13	1971-08-31
1972	1972-05-14	1972-09-16
1973	1973-05-14	1973-09-13
1974	1974-06-12	1974-09-26
1975	1975-06-01	1975-09-16
1976	1976-05-09	1976-09-30
1977	1977-04-25	1977-08-24
1978	1978-06-03	1978-08-29
1979	1979-05-22	1979-09-21
1980	1980-05-05	1980-09-30
1981	1981-04-24	1981-09-19
1982	1982-05-26	1982-09-09
1983	1983-05-21	1983-08-28
1984	1984-05-30	1984-09-19
1985	1985-05-17	1985-08-30
1987	1987-04-27	1987-09-23
1988	1988-05-11	1988-09-14
1990	1990-05-06	1990-09-26
1991	1991-06-11	1991-09-13
1993	1993-05-11	1993-09-11
1997	1997-05-12	1997-09-27
1999	1999-05-24	1999-09-25
2000	2000-05-17	2000-09-19
2001	2001-05-13	2001-09-25
2002	2002-06-13	2002-09-20
2003	2003-05-24	2003-09-29
2004	2004-06-04	2004-09-09
2005	2005-05-27	2005-09-09
2006	2006-05-16	2006-09-30
2007	2007-05-09	2007-09-14
2011	2011-06-22	2011-09-25
2013	2013-05-07	2013-09-16
2016	2016-04-20	2016-09-17
2017	2017-05-23	2017-08-31
2018	2018-05-14	2018-09-08
2019	2019-05-12	2019-09-08
2020	2020-05-29	2020-10-07
2021	2021-04-30	2021-09-26
2022	2022-06-23	2022-09-08
2023	2023-05-04	2023-09-18
2024	2024-05-12	2024-09-27
2025	2025-05-26	2025-09-21
2026	2026-05-03	2026-09-24

Every Fixed Threshold

Fixed thresholds at Prosser
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	79	88	2025	87
35 C (95 F): Days	79	43	2021	29
40 C (104 F): Days	25	5	1938	4
45 C (113 F): Days	1	1	2021	1
90 F (32.2 C): Days	79	64	1958	62
100 F (37.8 C): Days	62	16	2021	13
110 F (43.3 C): Days	3	4	2021	4
0 C (32 F): Ice days (max	78	66	1985	3
0 C (32 F): Frost days (min	78	156	1955	52
-10 C (14 F): Days with min	73	33	1949	16
-20 C (-4 F): Days with min	24	11	1950	1
20 C (68 F): Tropical nights (min	47	18	2004	11
10 mm (0.39 in): Days with 10 mm or more rain	78	8	1961	6
25 mm (0.98 in): Days with 25 mm or more rain	10	2	1957	1
10 cm (3.9 in): Days with 10 cm or more snowfall	15	2	1942	1
25 cm (9.8 in): Days with 25 cm or more snowfall	1	1	2021	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1931.

Download the Data

Data for Prosser threshold days by year: CSV or JSON. Field meanings are on the data page.

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 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Prosser Threshold Days by Year (USC00456768)

Key Facts for Prosser Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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