Chelsea Threshold Days by Year (USC00431360)

19 fixed thresholds counted per year at Chelsea (USC00431360): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Chelsea Thresholds

Chelsea: nights with a minimum temperature at or below 0 C (32 F) in 98 years, most in 1956 with 226.
Chelsea: nights with a minimum temperature at or below -10 C (14 F) in 98 years, most in 1978 with 107.
Chelsea: nights with a minimum temperature at or below -20 C (-4 F) in 98 years, most in 1962 with 55.
Chelsea: days with a maximum temperature at or below 0 C (32 F) in 97 years, most in 1904 with 103.
19 fixed thresholds have at least one qualifying day at Chelsea.

Days at or above 30 C (86 F)

96 years with a qualifying day

Days per year at Chelsea with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 40 in 1955.

Days at or above 30 C (86 F) per year at Chelsea
Year	Days	Decade average
1896	4	4.8
1897	7	4.8
1898	4	4.8
1899	4	4.8
1900	5	4.6
1901	10	4.6
1903	4	4.6
1904	2	4.6
1905	3	4.6
1906	2	4.6
1907	3	4.6
1908	8	4.6
1910	6	14.4
1913	16	14.4
1915	10	14.4
1916	25	14.4
1918	15	14.4
1920	8	12.5
1921	27	12.5
1922	12	12.5
1923	13	12.5
1924	11	12.5
1925	10	12.5
1926	5	12.5
1927	4	12.5
1928	16	12.5
1929	19	12.5
1931	17	19
1932	8	19
1933	17	19
1934	18	19
1935	16	19
1936	21	19
1937	37	19
1938	13	19
1939	24	19
1940	21	22.5
1941	26	22.5
1942	24	22.5
1943	9	22.5
1944	31	22.5
1945	19	22.5
1946	16	22.5
1947	28	22.5
1948	16	22.5
1949	35	22.5
1950	13	21.1
1951	13	21.1
1952	24	21.1
1953	34	21.1
1954	8	21.1
1955	40	21.1
1956	10	21.1
1957	18	21.1
1958	11	21.1
1959	40	21.1
1960	14	14.1
1961	13	14.1
1962	6	14.1
1963	14	14.1
1964	14	14.1
1965	24	14.1
1966	20	14.1
1967	8	14.1
1968	13	14.1
1969	15	14.1
1970	25	19
1971	22	19
1972	12	19
1973	26	19
1974	11	19
1975	27	19
1976	14	19
1977	18	19
1978	21	19
1979	14	19
1980	13	11.1
1981	3	11.1
1982	8	11.1
1983	12	11.1
1984	10	11.1
1985	6	11.1
1986	4	11.1
1987	17	11.1
1988	26	11.1
1989	12	11.1
1990	13	12.5
1991	13	12.5
1992	5	12.5
1993	16	12.5
1994	11	12.5
1995	18	12.5
1996	5	12.5
1997	10	12.5
1998	10	12.5
1999	24	12.5

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

First to last qualifying date each year at Chelsea
Year	First date	Last date
1896	1896-07-02	1896-09-12
1897	1897-07-05	1897-09-10
1898	1898-07-03	1898-07-26
1899	1899-06-05	1899-08-19
1900	1900-07-07	1900-08-26
1901	1901-06-21	1901-07-18
1903	1903-06-03	1903-07-10
1904	1904-06-26	1904-07-19
1905	1905-06-18	1905-07-18
1906	1906-07-15	1906-08-06
1907	1907-06-25	1907-07-18
1908	1908-06-08	1908-07-31
1910	1910-06-15	1910-07-10
1913	1913-06-16	1913-09-03
1915	1915-04-27	1915-09-17
1916	1916-07-07	1916-08-25
1918	1918-06-01	1918-08-24
1920	1920-06-01	1920-08-16
1921	1921-05-21	1921-09-03
1922	1922-06-08	1922-10-01
1923	1923-06-04	1923-07-22
1924	1924-07-06	1924-09-01
1925	1925-06-03	1925-09-12
1926	1926-07-19	1926-08-03
1927	1927-06-23	1927-07-14
1928	1928-07-03	1928-09-17
1929	1929-05-28	1929-09-04
1931	1931-05-20	1931-09-15
1932	1932-05-17	1932-09-02
1933	1933-06-09	1933-08-01
1934	1934-05-22	1934-09-26
1935	1935-06-30	1935-08-19
1936	1936-05-08	1936-08-16
1937	1937-05-31	1937-09-24
1938	1938-06-21	1938-08-16
1939	1939-06-09	1939-09-16
1940	1940-06-05	1940-08-18
1941	1941-04-20	1941-09-22
1942	1942-05-29	1942-09-18
1943	1943-06-24	1943-08-23
1944	1944-05-04	1944-09-02
1945	1945-06-15	1945-09-08
1946	1946-06-24	1946-09-18
1947	1947-06-11	1947-10-17
1948	1948-06-04	1948-09-13
1949	1949-05-05	1949-08-28
1950	1950-06-08	1950-08-28
1951	1951-05-17	1951-08-31
1952	1952-06-18	1952-09-12
1953	1953-05-11	1953-09-06
1954	1954-06-02	1954-08-26
1955	1955-05-05	1955-09-20
1956	1956-06-13	1956-09-06
1957	1957-05-10	1957-09-23
1958	1958-07-02	1958-09-01
1959	1959-05-21	1959-09-10
1960	1960-06-18	1960-09-10
1961	1961-05-15	1961-09-24
1962	1962-04-28	1962-09-01
1963	1963-06-25	1963-07-30
1964	1964-05-24	1964-08-31
1965	1965-05-27	1965-09-24
1966	1966-05-25	1966-08-10
1967	1967-06-04	1967-07-22
1968	1968-06-07	1968-08-26
1969	1969-06-13	1969-09-02
1970	1970-05-02	1970-09-23
1971	1971-05-20	1971-09-06
1972	1972-05-29	1972-08-26
1973	1973-06-12	1973-09-06
1974	1974-05-16	1974-08-23
1975	1975-05-21	1975-08-12
1976	1976-04-18	1976-08-23
1977	1977-05-18	1977-08-30
1978	1978-05-27	1978-08-20
1979	1979-05-10	1979-08-06
1980	1980-06-25	1980-08-27
1981	1981-06-17	1981-07-10
1982	1982-07-08	1982-09-14
1983	1983-06-14	1983-08-09
1984	1984-06-09	1984-08-07
1985	1985-07-16	1985-08-16
1986	1986-05-19	1986-07-25
1987	1987-05-31	1987-08-18
1988	1988-06-13	1988-08-15
1989	1989-05-19	1989-09-11
1990	1990-04-28	1990-08-27
1991	1991-05-25	1991-08-31
1992	1992-05-23	1992-08-28
1993	1993-06-15	1993-08-29
1994	1994-05-23	1994-07-23
1995	1995-06-19	1995-08-22
1996	1996-05-21	1996-08-08
1997	1997-06-11	1997-08-12
1998	1998-05-30	1998-08-10
1999	1999-05-31	1999-09-05

Every Fixed Threshold

Fixed thresholds at Chelsea
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	96	40	1955	24
35 C (95 F): Days	28	4	1952	1
90 F (32.2 C): Days	78	19	1944	6
100 F (37.8 C): Days	1	1	1937	1
0 C (32 F): Ice days (max	97	103	1904	52
0 C (32 F): Frost days (min	98	226	1956	190
-10 C (14 F): Days with min	98	107	1978	68
-20 C (-4 F): Days with min	98	55	1962	28
-30 C (-22 F): Days with min	82	17	1963	1
-40 C (-40 F): Days with min	1	1	1943	1
20 C (68 F): Tropical nights (min	27	3	1916	1
25 C (77 F): Days with min	1	1	1897	1
10 mm (0.39 in): Days with 10 mm or more rain	95	51	1983	35
25 mm (0.98 in): Days with 25 mm or more rain	95	14	1976	6
50 mm (1.97 in): Days with 50 mm or more rain	52	4	1927	2
100 mm (3.94 in): Days with 100 mm or more rain	2	1	1927	1
10 cm (3.9 in): Days with 10 cm or more snowfall	54	13	1956	3
25 cm (9.8 in): Days with 25 cm or more snowfall	27	4	1971	1
50 cm (19.7 in): Days with 50 cm or more snowfall	1	1	1984	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1896.

Download the Data

Data for Chelsea 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).

Chelsea Threshold Days by Year (USC00431360)

Key Facts for Chelsea Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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