Runnymede Threshold Days by Year

3 fixed thresholds counted per year at Runnymede (ASN00081042): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Runnymede Thresholds

Runnymede: days with 10 mm (0.39 in) or more of precipitation in 64 years, most in 1887 with 24.
Runnymede: days with 25 mm (0.98 in) or more of precipitation in 51 years, most in 1889 with 8.
Runnymede: days with 50 mm (1.97 in) or more of precipitation in 15 years, most in 1949 with 3.
3 fixed thresholds have at least one qualifying day at Runnymede.

Days with 10 mm (0.39 in) or more of precipitation

64 years with a qualifying day

Days per year at Runnymede with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 24 in 1887.

Days with 10 mm (0.39 in) or more of precipitation per year at Runnymede
Year	Days	Decade average
1887	24	17.3
1888	9	17.3
1889	19	17.3
1890	24	14
1891	17	14
1892	17	14
1894	19	14
1895	11	14
1896	9	14
1897	10	14
1898	7	14
1899	12	14
1900	11	11.5
1901	6	11.5
1902	6	11.5
1903	17	11.5
1904	13	11.5
1905	10	11.5
1906	18	11.5
1907	7	11.5
1908	9	11.5
1909	18	11.5
1910	15	13
1912	14	13
1913	14	13
1914	10	13
1915	11	13
1916	19	13
1919	8	13
1920	18	11.7
1921	21	11.7
1922	6	11.7
1923	12	11.7
1924	16	11.7
1925	6	11.7
1926	9	11.7
1927	6	11.7
1928	17	11.7
1929	6	11.7
1930	18	13.9
1931	18	13.9
1932	17	13.9
1933	11	13.9
1934	17	13.9
1935	18	13.9
1936	14	13.9
1937	8	13.9
1938	2	13.9
1939	16	13.9
1940	6	10.8
1941	12	10.8
1942	15	10.8
1943	7	10.8
1944	5	10.8
1945	9	10.8
1946	13	10.8
1947	12	10.8
1948	12	10.8
1949	17	10.8
1950	18	14.8
1951	16	14.8
1952	13	14.8
1953	14	14.8
1954	13	14.8

For each year, a bar from the first to the last day at Runnymede meeting 10 mm (0.39 in).

First to last qualifying date each year at Runnymede
Year	First date	Last date
1887	1887-02-14	1887-12-03
1888	1888-01-13	1888-12-31
1889	1889-01-01	1889-11-16
1890	1890-03-17	1890-12-22
1891	1891-01-09	1891-12-14
1892	1892-03-23	1892-12-10
1894	1894-02-28	1894-12-15
1895	1895-01-05	1895-12-11
1896	1896-02-11	1896-12-02
1897	1897-01-09	1897-09-28
1898	1898-02-12	1898-09-05
1899	1899-01-19	1899-08-04
1900	1900-01-08	1900-12-03
1901	1901-04-22	1901-10-12
1902	1902-03-27	1902-12-18
1903	1903-03-05	1903-12-28
1904	1904-01-02	1904-11-02
1905	1905-04-05	1905-12-31
1906	1906-02-28	1906-12-18
1907	1907-01-26	1907-12-28
1908	1908-01-10	1908-12-22
1909	1909-01-04	1909-12-01
1910	1910-01-04	1910-12-09
1912	1912-02-24	1912-12-04
1913	1913-01-03	1913-11-11
1914	1914-01-26	1914-12-25
1915	1915-01-31	1915-10-23
1916	1916-01-28	1916-12-13
1919	1919-02-18	1919-12-28
1920	1920-05-11	1920-12-27
1921	1921-01-02	1921-12-23
1922	1922-02-28	1922-10-01
1923	1923-05-08	1923-11-04
1924	1924-01-03	1924-12-26
1925	1925-01-13	1925-11-18
1926	1926-01-08	1926-08-30
1927	1927-05-11	1927-12-19
1928	1928-01-18	1928-12-11
1929	1929-02-16	1929-12-02
1930	1930-03-13	1930-12-26
1931	1931-03-02	1931-11-16
1932	1932-02-09	1932-12-16
1933	1933-01-21	1933-11-29
1934	1934-01-07	1934-12-01
1935	1935-01-05	1935-12-25
1936	1936-01-09	1936-12-18
1937	1937-01-25	1937-12-11
1938	1938-02-05	1938-06-15
1939	1939-02-17	1939-11-16
1940	1940-03-19	1940-11-12
1941	1941-01-04	1941-11-05
1942	1942-01-20	1942-11-22
1943	1943-01-03	1943-11-18
1944	1944-04-24	1944-12-21
1945	1945-01-14	1945-10-26
1946	1946-01-18	1946-11-27
1947	1947-01-04	1947-11-04
1948	1948-02-14	1948-12-27
1949	1949-02-21	1949-11-22
1950	1950-02-05	1950-12-20
1951	1951-01-07	1951-12-10
1952	1952-01-05	1952-12-11
1953	1953-01-07	1953-12-07
1954	1954-01-29	1954-12-04

Every Fixed Threshold

Fixed thresholds at Runnymede
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
10 mm (0.39 in): Days with 10 mm or more rain	64	24	1887	13
25 mm (0.98 in): Days with 25 mm or more rain	51	8	1889	3
50 mm (1.97 in): Days with 50 mm or more rain	15	3	1949	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1887.

Download the Data

Data for Runnymede 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).

Runnymede Threshold Days by Year

Key Facts for Runnymede Thresholds

Days with 10 mm (0.39 in) or more of precipitation

Every Fixed Threshold

Download the Data

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