Chelsea Threshold Days by Year (CA007031360)

16 fixed thresholds counted per year at Chelsea (CA007031360): 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 55 years, most in 1956 with 195.
Chelsea: nights with a minimum temperature at or below -10 C (14 F) in 55 years, most in 1943 with 104.
Chelsea: nights with a minimum temperature at or below -20 C (-4 F) in 55 years, most in 1934 with 58.
Chelsea: days with 10 mm (0.39 in) or more of precipitation in 55 years, most in 1972 with 46.
16 fixed thresholds have at least one qualifying day at Chelsea.

Days at or above 30 C (86 F)

54 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 35 in 1955.

Days at or above 30 C (86 F) per year at Chelsea
Year	Days	Decade average
1928	8	10.5
1929	13	10.5
1930	4	10.4
1931	15	10.4
1932	6	10.4
1933	10	10.4
1934	12	10.4
1935	11	10.4
1936	5	10.4
1938	18	10.4
1939	13	10.4
1940	12	14
1941	17	14
1942	7	14
1943	6	14
1944	22	14
1945	10	14
1947	16	14
1948	8	14
1949	28	14
1950	7	10.6
1951	1	10.6
1952	11	10.6
1953	16	10.6
1954	3	10.6
1955	35	10.6
1956	4	10.6
1957	7	10.6
1958	4	10.6
1959	18	10.6
1960	5	8.8
1961	6	8.8
1962	8	8.8
1963	16	8.8
1964	8	8.8
1965	5	8.8
1966	15	8.8
1967	7	8.8
1968	7	8.8
1969	11	8.8
1970	19	12.3
1971	9	12.3
1972	4	12.3
1973	10	12.3
1974	7	12.3
1975	25	12.3
1976	11	12.3
1977	12	12.3
1978	13	12.3
1979	13	12.3
1980	6	12.3
1981	8	12.3
1982	9	12.3
1983	26	12.3

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
1928	1928-07-04	1928-08-28
1929	1929-05-28	1929-09-04
1930	1930-06-04	1930-07-20
1931	1931-06-20	1931-09-14
1932	1932-05-26	1932-08-27
1933	1933-06-09	1933-08-07
1934	1934-06-04	1934-08-19
1935	1935-07-04	1935-08-20
1936	1936-05-08	1936-08-09
1938	1938-06-20	1938-08-20
1939	1939-05-08	1939-09-16
1940	1940-06-04	1940-08-18
1941	1941-06-19	1941-08-08
1942	1942-06-12	1942-08-22
1943	1943-06-04	1943-08-02
1944	1944-05-30	1944-08-16
1945	1945-06-30	1945-09-08
1947	1947-06-11	1947-09-11
1948	1948-06-24	1948-08-28
1949	1949-06-03	1949-09-04
1950	1950-06-08	1950-07-13
1951	1951-07-25	1951-07-25
1952	1952-07-06	1952-08-28
1953	1953-05-10	1953-09-04
1954	1954-07-01	1954-08-25
1955	1955-06-06	1955-09-19
1956	1956-06-12	1956-06-15
1957	1957-06-15	1957-08-03
1958	1958-07-01	1958-08-07
1959	1959-06-08	1959-08-26
1960	1960-07-12	1960-09-07
1961	1961-07-23	1961-09-11
1962	1962-05-17	1962-08-31
1963	1963-06-24	1963-07-28
1964	1964-05-23	1964-07-28
1965	1965-05-26	1965-08-15
1966	1966-06-23	1966-08-18
1967	1967-06-03	1967-08-17
1968	1968-07-01	1968-07-22
1969	1969-06-12	1969-08-31
1970	1970-06-02	1970-08-15
1971	1971-05-19	1971-08-19
1972	1972-05-23	1972-07-21
1973	1973-07-07	1973-09-05
1974	1974-06-10	1974-08-23
1975	1975-05-20	1975-08-10
1976	1976-04-18	1976-08-22
1977	1977-05-17	1977-09-01
1978	1978-05-25	1978-08-15
1979	1979-05-09	1979-07-25
1980	1980-05-31	1980-08-25
1981	1981-06-16	1981-08-02
1982	1982-07-06	1982-08-09
1983	1983-06-12	1983-09-20

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	54	35	1955	26
35 C (95 F): Days	7	5	1944	1
90 F (32.2 C): Days	43	15	1955	5
0 C (32 F): Ice days (max	54	103	1955	80
0 C (32 F): Frost days (min	55	195	1956	165
-10 C (14 F): Days with min	55	104	1943	70
-20 C (-4 F): Days with min	55	58	1934	23
-30 C (-22 F): Days with min	46	19	1934	7
-40 C (-40 F): Days with min	2	1	1933	1
20 C (68 F): Tropical nights (min	43	9	1947	5
25 C (77 F): Days with min	1	1	1947	1
10 mm (0.39 in): Days with 10 mm or more rain	55	46	1972	30
25 mm (0.98 in): Days with 25 mm or more rain	53	13	1972	2
50 mm (1.97 in): Days with 50 mm or more rain	11	2	1943	1
10 cm (3.9 in): Days with 10 cm or more snowfall	55	14	1954	6
25 cm (9.8 in): Days with 25 cm or more snowfall	18	3	1972	2

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1928.

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

Chelsea Threshold Days by Year (CA007031360)

Key Facts for Chelsea Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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