Redwood City Threshold Days by Year (USC00047339)

12 fixed thresholds counted per year at Redwood City (USC00047339): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Redwood City Thresholds

Redwood City: days with a maximum temperature at or above 30 C (86 F) in 89 years, most in 1978 with 60.
Redwood City: days with a maximum temperature at or above 35 C (95 F) in 89 years, most in 1983 with 20.
Redwood City: days with a maximum temperature at or above 90 F (32.2 C) in 89 years, most in 1970 with 34.
Redwood City: days with 10 mm (0.39 in) or more of precipitation in 88 years, most in 1983 with 39.
12 fixed thresholds have at least one qualifying day at Redwood City.

Days at or above 30 C (86 F)

89 years with a qualifying day

Days per year at Redwood City with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 60 in 1978.

Days at or above 30 C (86 F) per year at Redwood City
Year	Days	Decade average
1931	42	34.6
1932	28	34.6
1933	23	34.6
1934	35	34.6
1935	31	34.6
1936	52	34.6
1937	27	34.6
1938	30	34.6
1939	43	34.6
1940	21	29.7
1941	28	29.7
1942	27	29.7
1943	28	29.7
1944	39	29.7
1945	38	29.7
1946	31	29.7
1947	39	29.7
1948	21	29.7
1949	25	29.7
1950	42	30.9
1951	19	30.9
1952	28	30.9
1953	25	30.9
1954	32	30.9
1955	25	30.9
1956	22	30.9
1957	34	30.9
1958	33	30.9
1959	49	30.9
1960	40	43.2
1961	49	43.2
1962	32	43.2
1963	39	43.2
1964	48	43.2
1965	38	43.2
1966	48	43.2
1967	48	43.2
1968	40	43.2
1969	50	43.2
1970	48	45.5
1971	50	45.5
1972	42	45.5
1973	39	45.5
1974	48	45.5
1975	43	45.5
1976	42	45.5
1977	36	45.5
1978	60	45.5
1979	47	45.5
1980	32	39.4
1981	48	39.4
1982	35	39.4
1983	59	39.4
1984	55	39.4
1985	36	39.4
1986	16	39.4
1987	34	39.4
1988	46	39.4
1989	33	39.4
1990	31	34
1991	26	34
1992	35	34
1993	49	34
1994	24	34
1995	40	34
1996	42	34
1997	31	34
1998	28	34
2003	43	34.3
2004	37	34.3
2007	28	34.3
2009	29	34.3
2010	22	31.7
2011	27	31.7
2012	31	31.7
2013	29	31.7
2014	38	31.7
2015	39	31.7
2016	27	31.7
2017	42	31.7
2018	24	31.7
2019	38	31.7
2020	48	32.6
2021	21	32.6
2022	37	32.6
2023	25	32.6
2024	38	32.6
2025	24	32.6
2026	35	32.6

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

First to last qualifying date each year at Redwood City
Year	First date	Last date
1931	1931-04-20	1931-10-01
1932	1932-05-25	1932-09-09
1933	1933-04-14	1933-10-19
1934	1934-05-10	1934-10-10
1935	1935-05-20	1935-09-19
1936	1936-04-12	1936-10-09
1937	1937-06-02	1937-10-21
1938	1938-04-18	1938-09-10
1939	1939-04-06	1939-10-30
1940	1940-04-12	1940-10-12
1941	1941-05-09	1941-10-16
1942	1942-05-19	1942-10-21
1943	1943-05-08	1943-10-06
1944	1944-05-02	1944-09-26
1945	1945-04-15	1945-10-02
1946	1946-04-23	1946-10-10
1947	1947-04-12	1947-10-04
1948	1948-06-22	1948-10-17
1949	1949-05-06	1949-10-01
1950	1950-04-18	1950-10-13
1951	1951-05-25	1951-10-07
1952	1952-05-17	1952-10-03
1953	1953-05-04	1953-10-05
1954	1954-04-15	1954-10-14
1955	1955-05-10	1955-09-12
1956	1956-05-15	1956-09-29
1957	1957-04-28	1957-09-21
1958	1958-05-15	1958-10-10
1959	1959-05-07	1959-10-24
1960	1960-04-04	1960-09-26
1961	1961-04-02	1961-10-16
1962	1962-04-12	1962-09-17
1963	1963-05-16	1963-09-28
1964	1964-04-13	1964-10-21
1965	1965-04-25	1965-10-25
1966	1966-03-31	1966-10-10
1967	1967-05-14	1967-11-02
1968	1968-04-26	1968-09-26
1969	1969-05-05	1969-09-26
1970	1970-05-01	1970-10-02
1971	1971-06-14	1971-10-13
1972	1972-05-01	1972-10-07
1973	1973-05-10	1973-09-29
1974	1974-05-25	1974-10-18
1975	1975-05-12	1975-10-20
1976	1976-05-11	1976-10-13
1977	1977-04-12	1977-09-09
1978	1978-05-02	1978-10-14
1979	1979-05-11	1979-09-30
1980	1980-05-19	1980-10-07
1981	1981-04-28	1981-10-01
1982	1982-05-23	1982-10-13
1983	1983-05-17	1983-10-26
1984	1984-04-14	1984-09-29
1985	1985-04-02	1985-10-05
1986	1986-05-16	1986-10-07
1987	1987-04-21	1987-10-07
1988	1988-04-10	1988-10-18
1989	1989-04-05	1989-10-10
1990	1990-04-13	1990-10-03
1991	1991-05-24	1991-10-21
1992	1992-05-02	1992-10-11
1993	1993-05-01	1993-10-26
1994	1994-06-09	1994-09-17
1995	1995-06-21	1995-11-08
1996	1996-04-29	1996-10-08
1997	1997-05-15	1997-10-16
1998	1998-06-14	1998-09-13
2003	2003-05-20	2003-10-28
2004	2004-04-25	2004-10-14
2007	2007-04-27	2007-10-23
2009	2009-04-20	2009-09-27
2010	2010-06-12	2010-10-14
2011	2011-03-31	2011-10-17
2012	2012-04-20	2012-10-18
2013	2013-04-22	2013-09-19
2014	2014-04-08	2014-10-13
2015	2015-03-14	2015-10-13
2016	2016-04-06	2016-10-08
2017	2017-05-01	2017-10-26
2018	2018-05-28	2018-09-20
2019	2019-04-23	2019-10-25
2020	2020-05-07	2020-10-20
2021	2021-05-10	2021-10-03
2022	2022-04-07	2022-10-19
2023	2023-04-27	2023-10-19
2024	2024-05-10	2024-10-08
2025	2025-03-24	2025-10-06
2026	2026-03-16	2026-10-08

Every Fixed Threshold

Fixed thresholds at Redwood City
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	89	60	1978	35
35 C (95 F): Days	89	20	1983	7
40 C (104 F): Days	20	4	1961	2
90 F (32.2 C): Days	89	34	1970	20
100 F (37.8 C): Days	59	9	1961	1
110 F (43.3 C): Days	2	2	1972	1
0 C (32 F): Frost days (min	81	40	1949	5
20 C (68 F): Tropical nights (min	13	5	2017	1
10 mm (0.39 in): Days with 10 mm or more rain	88	39	1983	10
25 mm (0.98 in): Days with 25 mm or more rain	86	12	1952	3
50 mm (1.97 in): Days with 50 mm or more rain	42	4	1982	1
100 mm (3.94 in): Days with 100 mm or more rain	6	1	1955	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 Redwood City 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).

Redwood City Threshold Days by Year (USC00047339)

Key Facts for Redwood City Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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