Osterley Threshold Days by Year

4 fixed thresholds counted per year at Osterley (ASN00095016): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Osterley Thresholds

Osterley: days with 10 mm (0.39 in) or more of precipitation in 97 years, most in 1924 with 39.
Osterley: days with 25 mm (0.98 in) or more of precipitation in 88 years, most in 1923 with 9.
Osterley: days with 50 mm (1.97 in) or more of precipitation in 19 years, most in 1938 with 2.
Osterley: days with 100 mm (3.94 in) or more of precipitation in 1 years, most in 1960 with 1.
4 fixed thresholds have at least one qualifying day at Osterley.

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

97 years with a qualifying day

Days per year at Osterley with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 39 in 1924.

Days with 10 mm (0.39 in) or more of precipitation per year at Osterley
Year	Days	Decade average
1911	19	21.2
1912	32	21.2
1913	19	21.2
1914	10	21.2
1915	24	21.2
1916	28	21.2
1917	22	21.2
1918	16	21.2
1919	21	21.2
1920	18	25.3
1921	16	25.3
1922	21	25.3
1923	29	25.3
1924	39	25.3
1927	24	25.3
1928	27	25.3
1929	28	25.3
1930	18	21.3
1931	28	21.3
1932	17	21.3
1933	15	21.3
1934	20	21.3
1935	32	21.3
1936	20	21.3
1937	21	21.3
1938	22	21.3
1939	20	21.3
1940	20	22.6
1942	22	22.6
1943	19	22.6
1944	26	22.6
1945	15	22.6
1946	24	22.6
1947	30	22.6
1948	26	22.6
1949	21	22.6
1950	17	22.1
1951	24	22.1
1952	27	22.1
1953	28	22.1
1954	20	22.1
1955	18	22.1
1956	25	22.1
1957	17	22.1
1958	27	22.1
1959	18	22.1
1960	15	17.2
1961	12	17.2
1962	25	17.2
1963	9	17.2
1964	20	17.2
1965	11	17.2
1966	19	17.2
1967	15	17.2
1968	23	17.2
1969	23	17.2
1970	27	21.9
1971	31	21.9
1972	23	21.9
1973	21	21.9
1977	13	21.9
1978	23	21.9
1979	15	21.9
1980	23	18.4
1982	13	18.4
1987	16	18.4
1988	25	18.4
1989	15	18.4
1990	21	22.1
1991	24	22.1
1992	22	22.1
1994	28	22.1
1995	26	22.1
1998	18	22.1
1999	16	22.1
2000	20	20.1
2001	22	20.1
2002	18	20.1
2003	22	20.1
2004	29	20.1
2005	21	20.1
2006	13	20.1
2007	15	20.1
2008	18	20.1
2009	23	20.1
2010	15	18.4
2011	24	18.4
2012	19	18.4
2013	26	18.4
2014	13	18.4
2015	15	18.4
2016	27	18.4
2018	13	18.4
2019	14	18.4
2022	16	9.3
2023	11	9.3
2025	1	9.3

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

First to last qualifying date each year at Osterley
Year	First date	Last date
1911	1911-01-01	1911-12-31
1912	1912-01-03	1912-12-24
1913	1913-01-03	1913-12-24
1914	1914-04-11	1914-12-27
1915	1915-03-07	1915-11-29
1916	1916-01-12	1916-12-30
1917	1917-01-03	1917-11-15
1918	1918-02-03	1918-12-04
1919	1919-01-21	1919-10-13
1920	1920-02-28	1920-12-16
1921	1921-01-03	1921-11-24
1922	1922-01-08	1922-12-24
1923	1923-01-07	1923-12-05
1924	1924-01-10	1924-11-28
1927	1927-01-19	1927-12-19
1928	1928-01-01	1928-11-09
1929	1929-01-10	1929-12-29
1930	1930-01-19	1930-12-25
1931	1931-01-23	1931-11-17
1932	1932-02-12	1932-12-02
1933	1933-01-05	1933-11-30
1934	1934-01-25	1934-12-30
1935	1935-01-05	1935-12-21
1936	1936-08-04	1936-12-19
1937	1937-01-02	1937-12-26
1938	1938-01-05	1938-12-13
1939	1939-02-17	1939-12-24
1940	1940-01-06	1940-12-10
1942	1942-01-06	1942-12-25
1943	1943-01-17	1943-12-05
1944	1944-01-03	1944-12-20
1945	1945-01-16	1945-12-27
1946	1946-02-04	1946-11-28
1947	1947-02-17	1947-12-22
1948	1948-03-19	1948-12-05
1949	1949-01-06	1949-11-25
1950	1950-03-13	1950-12-20
1951	1951-01-08	1951-12-31
1952	1952-01-08	1952-11-27
1953	1953-01-06	1953-12-14
1954	1954-01-28	1954-11-21
1955	1955-03-05	1955-12-29
1956	1956-01-01	1956-11-25
1957	1957-02-09	1957-12-12
1958	1958-02-01	1958-12-17
1959	1959-01-07	1959-12-26
1960	1960-04-17	1960-11-01
1961	1961-01-11	1961-12-09
1962	1962-01-10	1962-11-24
1963	1963-01-06	1963-09-15
1964	1964-01-10	1964-11-28
1965	1965-01-11	1965-11-12
1966	1966-02-05	1966-12-16
1967	1967-03-04	1967-12-13
1968	1968-02-27	1968-12-10
1969	1969-01-26	1969-12-13
1970	1970-01-03	1970-12-31
1971	1971-01-16	1971-12-10
1972	1972-01-01	1972-12-25
1973	1973-01-13	1973-12-22
1977	1977-01-16	1977-12-17
1978	1978-02-05	1978-12-26
1979	1979-01-08	1979-12-02
1980	1980-02-09	1980-12-29
1982	1982-01-07	1982-12-08
1987	1987-01-09	1987-11-25
1988	1988-01-31	1988-12-11
1989	1989-01-05	1989-12-27
1990	1990-01-03	1990-12-28
1991	1991-01-24	1991-12-19
1992	1992-01-04	1992-11-30
1994	1994-01-07	1994-11-15
1995	1995-01-05	1995-12-19
1998	1998-01-28	1998-12-27
1999	1999-02-07	1999-11-07
2000	2000-01-05	2000-12-25
2001	2001-01-25	2001-12-21
2002	2002-03-21	2002-11-01
2003	2003-03-08	2003-12-22
2004	2004-01-08	2004-11-07
2005	2005-01-10	2005-12-25
2006	2006-01-01	2006-10-28
2007	2007-01-06	2007-12-22
2008	2008-02-24	2008-11-22
2009	2009-01-16	2009-12-18
2010	2010-02-05	2010-12-20
2011	2011-01-13	2011-12-26
2012	2012-01-31	2012-12-15
2013	2013-01-11	2013-12-11
2014	2014-01-06	2014-12-11
2015	2015-01-14	2015-12-27
2016	2016-01-29	2016-12-01
2018	2018-02-15	2018-10-18
2019	2019-03-22	2019-12-04
2022	2022-01-08	2022-12-14
2023	2023-01-22	2023-12-14
2025	2025-03-13	2025-03-13

Every Fixed Threshold

Fixed thresholds at Osterley
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	97	39	1924	1
25 mm (0.98 in): Days with 25 mm or more rain	88	9	1923	1
50 mm (1.97 in): Days with 50 mm or more rain	19	2	1938	1
100 mm (3.94 in): Days with 100 mm or more rain	1	1	1960	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1911.

Download the Data

Data for Osterley 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 2026-10-16 (16 October 2026). Threshold counts are computed by this site.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Osterley Threshold Days by Year

Key Facts for Osterley Thresholds

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

Every Fixed Threshold

Download the Data

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