Santa Rosa Threshold Days by Year (USC00298107)

17 fixed thresholds counted per year at Santa Rosa (USC00298107): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Santa Rosa Thresholds

Santa Rosa: days with 10 mm (0.39 in) or more of precipitation in 90 years, most in 1941 with 30.
Santa Rosa: days with 25 mm (0.98 in) or more of precipitation in 83 years, most in 1941 with 9.
Santa Rosa: nights with a minimum temperature at or below 0 C (32 F) in 81 years, most in 1999 with 147.
Santa Rosa: nights with a minimum temperature at or below -10 C (14 F) in 80 years, most in 1930 with 23.
17 fixed thresholds have at least one qualifying day at Santa Rosa.

Days at or above 30 C (86 F)

76 years with a qualifying day

Days per year at Santa Rosa with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 138 in 2000.

Days at or above 30 C (86 F) per year at Santa Rosa
Year	Days	Decade average
1919	110	110
1920	109	105.5
1925	115	105.5
1926	117	105.5
1927	109	105.5
1928	106	105.5
1929	77	105.5
1930	97	103.3
1931	87	103.3
1933	108	103.3
1934	127	103.3
1935	102	103.3
1936	106	103.3
1937	101	103.3
1938	87	103.3
1939	115	103.3
1940	92	82
1941	38	82
1944	49	82
1945	73	82
1947	109	82
1948	129	82
1949	84	82
1950	92	113
1951	105	113
1952	109	113
1953	113	113
1954	133	113
1955	117	113
1956	134	113
1958	101	113
1959	113	113
1960	123	115.9
1961	115	115.9
1962	129	115.9
1963	131	115.9
1964	122	115.9
1965	111	115.9
1966	106	115.9
1967	109	115.9
1968	110	115.9
1969	103	115.9
1971	110	105.4
1972	103	105.4
1973	109	105.4
1974	118	105.4
1975	101	105.4
1976	99	105.4
1977	111	105.4
1978	75	105.4
1979	123	105.4
1980	111	103.1
1981	109	103.1
1982	101	103.1
1983	110	103.1
1984	108	103.1
1985	95	103.1
1986	92	103.1
1987	95	103.1
1988	86	103.1
1989	124	103.1
1990	99	102.7
1991	94	102.7
1992	104	102.7
1993	101	102.7
1994	116	102.7
1995	102	102.7
1996	100	102.7
1997	100	102.7
1998	113	102.7
1999	98	102.7
2000	138	116.4
2001	117	116.4
2002	102	116.4
2003	113	116.4
2009	112	116.4

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

First to last qualifying date each year at Santa Rosa
Year	First date	Last date
1919	1919-04-22	1919-09-29
1920	1920-05-02	1920-10-09
1925	1925-04-12	1925-10-06
1926	1926-05-20	1926-10-28
1927	1927-04-25	1927-10-05
1928	1928-04-29	1928-10-08
1929	1929-05-10	1929-10-06
1930	1930-04-07	1930-10-09
1931	1931-05-24	1931-09-27
1933	1933-05-17	1933-09-30
1934	1934-04-10	1934-10-26
1935	1935-05-11	1935-10-04
1936	1936-04-14	1936-09-23
1937	1937-04-15	1937-09-27
1938	1938-04-30	1938-09-30
1939	1939-04-22	1939-10-06
1940	1940-04-21	1940-09-19
1941	1941-05-08	1941-09-06
1944	1944-05-12	1944-09-21
1945	1945-05-11	1945-09-18
1947	1947-05-02	1947-10-10
1948	1948-04-07	1948-09-25
1949	1949-04-13	1949-09-17
1950	1950-04-21	1950-10-30
1951	1951-05-05	1951-10-11
1952	1952-05-04	1952-10-25
1953	1953-05-20	1953-10-10
1954	1954-04-04	1954-10-13
1955	1955-05-06	1955-10-20
1956	1956-05-03	1956-10-10
1958	1958-04-22	1958-10-08
1959	1959-04-05	1959-10-25
1960	1960-04-06	1960-10-08
1961	1961-04-04	1961-10-07
1962	1962-04-14	1962-10-14
1963	1963-05-03	1963-10-15
1964	1964-05-11	1964-10-17
1965	1965-04-20	1965-10-13
1966	1966-03-31	1966-09-29
1967	1967-03-28	1967-10-09
1968	1968-05-02	1968-10-29
1969	1969-04-29	1969-10-02
1971	1971-03-26	1971-10-14
1972	1972-02-28	1972-10-11
1973	1973-05-09	1973-10-23
1974	1974-05-02	1974-09-29
1975	1975-05-12	1975-10-12
1976	1976-05-11	1976-10-12
1977	1977-05-23	1977-09-30
1978	1978-05-12	1978-10-12
1979	1979-04-15	1979-10-27
1980	1980-04-19	1980-10-05
1981	1981-04-10	1981-09-30
1982	1982-05-19	1982-09-27
1983	1983-05-24	1983-09-28
1984	1984-04-17	1984-09-25
1985	1985-06-01	1985-10-06
1986	1986-04-29	1986-09-22
1987	1987-04-17	1987-10-12
1988	1988-04-08	1988-10-17
1989	1989-03-10	1989-10-15
1990	1990-04-14	1990-09-27
1991	1991-04-06	1991-10-17
1992	1992-04-28	1992-10-13
1993	1993-04-22	1993-10-06
1994	1994-04-18	1994-09-30
1995	1995-05-15	1995-10-18
1996	1996-04-24	1996-10-13
1997	1997-03-21	1997-10-05
1998	1998-05-13	1998-10-14
1999	1999-04-20	1999-10-14
2000	2000-04-17	2000-10-04
2001	2001-05-01	2001-10-20
2002	2002-05-06	2002-09-21
2003	2003-05-12	2003-10-23
2009	2009-04-22	2009-10-01

Every Fixed Threshold

Fixed thresholds at Santa Rosa
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	76	138	2000	112
35 C (95 F): Days	74	61	1964	27
40 C (104 F): Days	21	6	1994	1
90 F (32.2 C): Days	76	109	1954	76
100 F (37.8 C): Days	61	22	1980	4
0 C (32 F): Ice days (max	68	11	1997	1
0 C (32 F): Frost days (min	81	147	1999	113
-10 C (14 F): Days with min	80	23	1930	10
-20 C (-4 F): Days with min	20	3	1929	1
-30 C (-22 F): Days with min	1	1	1963	1
20 C (68 F): Tropical nights (min	70	93	1919	6
25 C (77 F): Days with min	5	3	1935	1
10 mm (0.39 in): Days with 10 mm or more rain	90	30	1941	5
25 mm (0.98 in): Days with 25 mm or more rain	83	9	1941	1
50 mm (1.97 in): Days with 50 mm or more rain	33	2	1927	1
10 cm (3.9 in): Days with 10 cm or more snowfall	53	6	1997	1
25 cm (9.8 in): Days with 25 cm or more snowfall	4	1	1958	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1919.

Download the Data

Data for Santa Rosa 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).

Santa Rosa Threshold Days by Year (USC00298107)

Key Facts for Santa Rosa Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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