Mortlake Threshold Days by Year (ASN00090058)

3 fixed thresholds counted per year at Mortlake (ASN00090058): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Mortlake Thresholds

Mortlake: days with 10 mm (0.39 in) or more of precipitation in 89 years, most in 1903 with 29.
Mortlake: days with 25 mm (0.98 in) or more of precipitation in 75 years, most in 1894 with 6.
Mortlake: days with 50 mm (1.97 in) or more of precipitation in 17 years, most in 1891 with 2.
3 fixed thresholds have at least one qualifying day at Mortlake.

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

89 years with a qualifying day

Days per year at Mortlake with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 29 in 1903.

Days with 10 mm (0.39 in) or more of precipitation per year at Mortlake
Year	Days	Decade average
1880	20	16.9
1881	14	16.9
1883	20	16.9
1884	22	16.9
1885	13	16.9
1886	11	16.9
1887	17	16.9
1888	15	16.9
1889	20	16.9
1890	12	18.7
1891	20	18.7
1892	18	18.7
1894	26	18.7
1895	22	18.7
1896	18	18.7
1897	14	18.7
1898	12	18.7
1899	26	18.7
1901	19	16.7
1902	10	16.7
1903	29	16.7
1904	19	16.7
1905	15	16.7
1906	18	16.7
1907	10	16.7
1908	13	16.7
1909	17	16.7
1910	19	16.8
1911	19	16.8
1912	12	16.8
1913	17	16.8
1914	8	16.8
1915	12	16.8
1916	19	16.8
1917	22	16.8
1918	24	16.8
1919	16	16.8
1920	10	16.4
1921	20	16.4
1922	19	16.4
1923	18	16.4
1924	20	16.4
1925	13	16.4
1926	17	16.4
1927	10	16.4
1928	19	16.4
1929	18	16.4
1930	21	18
1931	18	18
1932	18	18
1933	16	18
1934	21	18
1935	25	18
1936	12	18
1937	20	18
1938	9	18
1939	20	18
1940	16	17.6
1941	24	17.6
1942	23	17.6
1943	13	17.6
1944	15	17.6
1945	12	17.6
1946	16	17.6
1947	21	17.6
1948	19	17.6
1949	17	17.6
1950	17	18.3
1951	17	18.3
1952	29	18.3
1953	16	18.3
1954	15	18.3
1955	21	18.3
1956	19	18.3
1957	15	18.3
1958	16	18.3
1959	18	18.3
1960	28	13.6
1961	15	13.6
1962	7	13.6
1963	9	13.6
1964	22	13.6
1965	10	13.6
1966	12	13.6
1967	6	13.6
1968	9	13.6
1969	18	13.6
1972	12	17.5
1973	23	17.5

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

First to last qualifying date each year at Mortlake
Year	First date	Last date
1880	1880-03-20	1880-12-15
1881	1881-01-19	1881-11-14
1883	1883-01-01	1883-11-15
1884	1884-01-22	1884-12-16
1885	1885-01-06	1885-12-22
1886	1886-01-08	1886-10-21
1887	1887-01-15	1887-11-06
1888	1888-03-04	1888-12-14
1889	1889-01-03	1889-12-21
1890	1890-05-28	1890-12-23
1891	1891-01-05	1891-12-14
1892	1892-03-15	1892-12-29
1894	1894-02-28	1894-12-24
1895	1895-01-04	1895-12-10
1896	1896-01-17	1896-12-28
1897	1897-01-09	1897-11-02
1898	1898-02-13	1898-11-22
1899	1899-01-20	1899-10-16
1901	1901-01-02	1901-11-15
1902	1902-01-04	1902-12-25
1903	1903-02-15	1903-12-27
1904	1904-01-03	1904-10-19
1905	1905-01-29	1905-12-10
1906	1906-02-28	1906-11-28
1907	1907-04-07	1907-12-29
1908	1908-01-09	1908-10-17
1909	1909-01-23	1909-12-01
1910	1910-03-06	1910-12-23
1911	1911-02-05	1911-12-12
1912	1912-03-28	1912-12-10
1913	1913-02-14	1913-11-24
1914	1914-03-13	1914-12-23
1915	1915-01-19	1915-11-23
1916	1916-01-28	1916-12-12
1917	1917-02-15	1917-11-26
1918	1918-01-13	1918-12-25
1919	1919-02-03	1919-12-27
1920	1920-03-06	1920-12-17
1921	1921-01-02	1921-12-02
1922	1922-01-08	1922-12-28
1923	1923-05-30	1923-12-14
1924	1924-01-28	1924-11-11
1925	1925-01-23	1925-12-24
1926	1926-05-03	1926-12-22
1927	1927-01-05	1927-12-01
1928	1928-01-18	1928-10-26
1929	1929-01-30	1929-12-28
1930	1930-02-21	1930-12-26
1931	1931-01-24	1931-11-16
1932	1932-02-05	1932-12-24
1933	1933-01-30	1933-11-30
1934	1934-01-07	1934-11-30
1935	1935-01-05	1935-12-02
1936	1936-01-04	1936-12-30
1937	1937-01-01	1937-12-08
1938	1938-02-05	1938-11-04
1939	1939-02-17	1939-12-05
1940	1940-01-06	1940-12-31
1941	1941-01-24	1941-12-04
1942	1942-01-20	1942-12-19
1943	1943-02-18	1943-11-04
1944	1944-02-07	1944-12-21
1945	1945-01-31	1945-12-27
1946	1946-01-04	1946-09-06
1947	1947-03-04	1947-12-23
1948	1948-01-06	1948-12-27
1949	1949-01-17	1949-11-22
1950	1950-02-15	1950-12-20
1951	1951-02-21	1951-12-14
1952	1952-01-04	1952-12-10
1953	1953-04-04	1953-11-27
1954	1954-01-28	1954-12-13
1955	1955-02-14	1955-12-31
1956	1956-01-02	1956-11-10
1957	1957-02-07	1957-12-26
1958	1958-01-31	1958-12-11
1959	1959-01-27	1959-12-28
1960	1960-01-09	1960-11-24
1961	1961-04-07	1961-12-15
1962	1962-03-28	1962-11-11
1963	1963-01-14	1963-09-11
1964	1964-01-15	1964-12-23
1965	1965-04-23	1965-12-02
1966	1966-02-14	1966-12-13
1967	1967-01-13	1967-12-30
1968	1968-03-29	1968-11-02
1969	1969-02-10	1969-12-11
1972	1972-01-12	1972-11-18
1973	1973-01-31	1973-12-22

Every Fixed Threshold

Fixed thresholds at Mortlake
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	89	29	1903	23
25 mm (0.98 in): Days with 25 mm or more rain	75	6	1894	2
50 mm (1.97 in): Days with 50 mm or more rain	17	2	1891	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1880.

Download the Data

Data for Mortlake 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).

Mortlake Threshold Days by Year (ASN00090058)

Key Facts for Mortlake Thresholds

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

Every Fixed Threshold

Download the Data

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