Serpentine Threshold Days by Year

4 fixed thresholds counted per year at Serpentine (ASN00009039): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Serpentine Thresholds

Serpentine: days with 10 mm (0.39 in) or more of precipitation in 96 years, most in 1917 with 53.
Serpentine: days with 25 mm (0.98 in) or more of precipitation in 96 years, most in 1921 with 17.
Serpentine: days with 50 mm (1.97 in) or more of precipitation in 53 years, most in 1937 with 3.
Serpentine: days with 100 mm (3.94 in) or more of precipitation in 4 years, most in 1955 with 1.
4 fixed thresholds have at least one qualifying day at Serpentine.

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

96 years with a qualifying day

Days per year at Serpentine with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 53 in 1917.

Days with 10 mm (0.39 in) or more of precipitation per year at Serpentine
Year	Days	Decade average
1907	40	34.3
1908	26	34.3
1909	37	34.3
1910	37	33.7
1911	22	33.7
1912	28	33.7
1913	33	33.7
1914	16	33.7
1915	49	33.7
1916	30	33.7
1917	53	33.7
1918	41	33.7
1919	28	33.7
1920	33	35.7
1921	40	35.7
1922	31	35.7
1923	42	35.7
1924	33	35.7
1925	28	35.7
1926	51	35.7
1927	31	35.7
1928	40	35.7
1929	28	35.7
1930	45	34.7
1931	33	34.7
1932	34	34.7
1933	36	34.7
1934	30	34.7
1935	31	34.7
1936	31	34.7
1937	38	34.7
1938	36	34.7
1939	33	34.7
1940	17	34.3
1941	36	34.3
1942	50	34.3
1943	31	34.3
1944	25	34.3
1945	42	34.3
1946	44	34.3
1947	38	34.3
1948	32	34.3
1949	28	34.3
1950	29	32
1951	32	32
1952	29	32
1953	32	32
1954	27	32
1955	45	32
1956	36	32
1957	35	32
1958	34	32
1959	21	32
1960	28	32.8
1961	33	32.8
1962	28	32.8
1963	41	32.8
1964	44	32.8
1965	36	32.8
1966	30	32.8
1967	30	32.8
1968	36	32.8
1969	22	32.8
1970	36	29
1971	28	29
1972	21	29
1973	39	29
1974	36	29
1975	25	29
1976	30	29
1977	24	29
1978	28	29
1979	23	29
1980	27	27
2001	25	26
2002	25	26
2005	28	26
2006	14	26
2007	31	26
2008	27	26
2009	32	26
2011	31	27.2
2012	26	27.2
2013	33	27.2
2014	27	27.2
2015	19	27.2
2016	37	27.2
2017	29	27.2
2018	23	27.2
2019	20	27.2
2020	23	25.7
2021	34	25.7
2022	28	25.7
2023	23	25.7
2024	20	25.7
2025	26	25.7

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

First to last qualifying date each year at Serpentine
Year	First date	Last date
1907	1907-04-27	1907-10-17
1908	1908-02-26	1908-10-11
1909	1909-03-28	1909-10-23
1910	1910-05-07	1910-11-20
1911	1911-04-23	1911-10-29
1912	1912-05-06	1912-11-13
1913	1913-04-11	1913-10-19
1914	1914-02-18	1914-11-13
1915	1915-01-08	1915-10-20
1916	1916-01-29	1916-11-23
1917	1917-02-10	1917-12-21
1918	1918-02-15	1918-10-29
1919	1919-01-17	1919-11-04
1920	1920-03-29	1920-10-10
1921	1921-03-22	1921-12-14
1922	1922-04-27	1922-12-07
1923	1923-01-20	1923-10-08
1924	1924-05-12	1924-11-10
1925	1925-03-06	1925-10-12
1926	1926-02-24	1926-11-27
1927	1927-03-13	1927-10-13
1928	1928-01-24	1928-11-02
1929	1929-01-02	1929-10-29
1930	1930-04-15	1930-11-14
1931	1931-04-12	1931-12-16
1932	1932-04-08	1932-10-28
1933	1933-01-08	1933-11-01
1934	1934-01-10	1934-10-24
1935	1935-01-06	1935-12-01
1936	1936-05-06	1936-12-18
1937	1937-01-11	1937-11-13
1938	1938-03-16	1938-11-02
1939	1939-01-29	1939-11-02
1940	1940-04-27	1940-10-21
1941	1941-04-15	1941-10-05
1942	1942-03-13	1942-12-01
1943	1943-01-31	1943-09-20
1944	1944-04-30	1944-12-07
1945	1945-05-04	1945-12-25
1946	1946-04-19	1946-11-13
1947	1947-04-17	1947-10-25
1948	1948-03-30	1948-12-24
1949	1949-03-12	1949-11-08
1950	1950-05-05	1950-11-08
1951	1951-02-22	1951-12-05
1952	1952-01-23	1952-10-31
1953	1953-02-02	1953-11-16
1954	1954-04-23	1954-11-11
1955	1955-02-15	1955-10-19
1956	1956-03-05	1956-11-29
1957	1957-04-22	1957-10-20
1958	1958-04-29	1958-12-21
1959	1959-04-28	1959-12-31
1960	1960-01-01	1960-09-23
1961	1961-03-27	1961-12-16
1962	1962-05-13	1962-12-06
1963	1963-02-20	1963-10-17
1964	1964-04-01	1964-12-19
1965	1965-03-26	1965-11-04
1966	1966-01-02	1966-12-27
1967	1967-04-11	1967-11-16
1968	1968-03-07	1968-11-18
1969	1969-04-08	1969-12-12
1970	1970-02-07	1970-11-04
1971	1971-03-27	1971-11-23
1972	1972-04-20	1972-10-08
1973	1973-04-24	1973-10-15
1974	1974-04-03	1974-10-23
1975	1975-05-05	1975-11-16
1976	1976-01-07	1976-11-12
1977	1977-02-21	1977-10-08
1978	1978-02-24	1978-10-01
1979	1979-04-15	1979-11-13
1980	1980-02-11	1980-12-31
2001	2001-05-06	2001-11-19
2002	2002-04-17	2002-11-01
2005	2005-04-01	2005-10-22
2006	2006-01-13	2006-11-29
2007	2007-04-16	2007-10-27
2008	2008-02-08	2008-11-23
2009	2009-01-30	2009-11-19
2011	2011-01-06	2011-12-13
2012	2012-01-20	2012-12-12
2013	2013-01-07	2013-11-30
2014	2014-03-23	2014-11-27
2015	2015-02-03	2015-12-05
2016	2016-01-31	2016-12-12
2017	2017-02-10	2017-12-18
2018	2018-01-16	2018-10-04
2019	2019-04-19	2019-10-05
2020	2020-03-15	2020-11-15
2021	2021-02-07	2021-10-20
2022	2022-04-26	2022-11-18
2023	2023-03-31	2023-10-02
2024	2024-05-29	2024-10-03
2025	2025-03-14	2025-11-01

Every Fixed Threshold

Fixed thresholds at Serpentine
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	96	53	1917	26
25 mm (0.98 in): Days with 25 mm or more rain	96	17	1921	6
50 mm (1.97 in): Days with 50 mm or more rain	53	3	1937	1
100 mm (3.94 in): Days with 100 mm or more rain	4	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 1907.

Download the Data

Data for Serpentine 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 2026-10-13 (13 October 2026). Threshold counts are computed by this site.

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

Serpentine Threshold Days by Year

Key Facts for Serpentine Thresholds

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

Every Fixed Threshold

Download the Data

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