Prosser Threshold Days by Year (USC00456763)

15 fixed thresholds counted per year at Prosser (USC00456763): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Prosser Thresholds

Prosser: nights with a minimum temperature at or below 0 C (32 F) in 47 years, most in 1944 with 151.
Prosser: days with a maximum temperature at or above 30 C (86 F) in 45 years, most in 1922 with 92.
Prosser: days with a maximum temperature at or above 35 C (95 F) in 45 years, most in 1914 with 37.
Prosser: days with a maximum temperature at or above 90 F (32.2 C) in 45 years, most in 1958 with 72.
15 fixed thresholds have at least one qualifying day at Prosser.

Days at or above 30 C (86 F)

45 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 92 in 1922.

Days at or above 30 C (86 F) per year at Prosser
Year	Days	Decade average
1913	60	65.6
1914	77	65.6
1915	72	65.6
1916	50	65.6
1917	72	65.6
1918	68	65.6
1919	60	65.6
1920	60	76
1921	61	76
1922	92	76
1925	78	76
1926	73	76
1928	87	76
1929	81	76
1930	60	73.6
1931	72	73.6
1932	72	73.6
1933	68	73.6
1934	86	73.6
1935	70	73.6
1936	80	73.6
1937	69	73.6
1938	86	73.6
1939	73	73.6
1940	88	68.9
1941	60	68.9
1942	67	68.9
1943	66	68.9
1944	66	68.9
1945	76	68.9
1947	59	68.9
1949	69	68.9
1950	80	64.4
1951	75	64.4
1952	69	64.4
1953	57	64.4
1954	47	64.4
1955	59	64.4
1956	70	64.4
1957	53	64.4
1958	88	64.4
1959	46	64.4
1960	64	62.3
1961	74	62.3
1962	49	62.3

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
1913	1913-05-22	1913-09-27
1914	1914-05-01	1914-09-10
1915	1915-04-17	1915-09-18
1916	1916-06-03	1916-09-21
1917	1917-05-28	1917-10-03
1918	1918-05-03	1918-09-29
1919	1919-05-18	1919-10-07
1920	1920-05-07	1920-09-17
1921	1921-05-24	1921-08-30
1922	1922-05-15	1922-09-30
1925	1925-04-09	1925-09-24
1926	1926-04-15	1926-09-06
1928	1928-05-05	1928-09-23
1929	1929-05-11	1929-10-15
1930	1930-06-06	1930-09-21
1931	1931-04-29	1931-10-01
1932	1932-05-08	1932-10-03
1933	1933-04-24	1933-09-13
1934	1934-04-19	1934-09-18
1935	1935-05-20	1935-10-02
1936	1936-04-12	1936-10-08
1937	1937-05-01	1937-09-18
1938	1938-05-22	1938-09-22
1939	1939-04-28	1939-09-26
1940	1940-05-09	1940-10-18
1941	1941-05-11	1941-09-25
1942	1942-04-20	1942-09-26
1943	1943-04-13	1943-09-25
1944	1944-05-14	1944-09-26
1945	1945-05-02	1945-09-14
1947	1947-04-13	1947-09-23
1949	1949-05-07	1949-09-27
1950	1950-05-12	1950-09-23
1951	1951-04-13	1951-09-19
1952	1952-04-18	1952-09-26
1953	1953-05-05	1953-09-18
1954	1954-05-16	1954-09-26
1955	1955-05-19	1955-09-11
1956	1956-04-20	1956-09-25
1957	1957-04-29	1957-09-15
1958	1958-05-16	1958-10-05
1959	1959-05-13	1959-09-13
1960	1960-05-10	1960-09-18
1961	1961-05-20	1961-09-04
1962	1962-06-08	1962-09-26

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	45	92	1922	49
35 C (95 F): Days	45	37	1914	12
40 C (104 F): Days	17	11	1914	1
90 F (32.2 C): Days	45	72	1958	26
100 F (37.8 C): Days	39	20	1914	1
110 F (43.3 C): Days	1	3	1928	3
0 C (32 F): Ice days (max	44	51	1916	11
0 C (32 F): Frost days (min	47	151	1944	87
-10 C (14 F): Days with min	44	36	1916	6
-20 C (-4 F): Days with min	18	9	1950	7
-30 C (-22 F): Days with min	1	1	1950	1
20 C (68 F): Tropical nights (min	23	9	1941	1
10 mm (0.39 in): Days with 10 mm or more rain	34	8	1942	4
25 mm (0.98 in): Days with 25 mm or more rain	5	2	1957	2
10 cm (3.9 in): Days with 10 cm or more snowfall	6	2	1950	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1913.

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 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Prosser Threshold Days by Year (USC00456763)

Key Facts for Prosser Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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