Grootdam Threshold Days by Year (SF001215980)

3 fixed thresholds counted per year at Grootdam (SF001215980): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Grootdam Thresholds

Grootdam: days with 10 mm (0.39 in) or more of precipitation in 76 years, most in 1985 with 26.
Grootdam: days with 25 mm (0.98 in) or more of precipitation in 71 years, most in 1974 with 10.
Grootdam: days with 50 mm (1.97 in) or more of precipitation in 17 years, most in 1974 with 2.
3 fixed thresholds have at least one qualifying day at Grootdam.

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

76 years with a qualifying day

Days per year at Grootdam with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 26 in 1985.

Days with 10 mm (0.39 in) or more of precipitation per year at Grootdam
Year	Days	Decade average
1915	9	11.4
1916	11	11.4
1917	14	11.4
1918	16	11.4
1919	7	11.4
1920	9	12.5
1921	12	12.5
1925	21	12.5
1926	8	12.5
1930	9	9.9
1931	11	9.9
1932	10	9.9
1933	10	9.9
1934	15	9.9
1935	9	9.9
1936	9	9.9
1937	9	9.9
1938	7	9.9
1939	10	9.9
1940	14	10.9
1942	10	10.9
1943	18	10.9
1944	13	10.9
1945	8	10.9
1946	11	10.9
1947	11	10.9
1948	9	10.9
1949	4	10.9
1950	20	13.1
1951	10	13.1
1952	15	13.1
1953	18	13.1
1954	9	13.1
1955	14	13.1
1956	11	13.1
1957	11	13.1
1958	10	13.1
1959	13	13.1
1960	10	10.4
1961	11	10.4
1962	9	10.4
1963	19	10.4
1964	10	10.4
1965	7	10.4
1966	4	10.4
1967	16	10.4
1968	8	10.4
1969	10	10.4
1970	11	15
1971	13	15
1972	14	15
1973	16	15
1974	22	15
1975	15	15
1976	24	15
1977	13	15
1978	6	15
1979	16	15
1980	4	15.2
1981	16	15.2
1982	16	15.2
1983	16	15.2
1984	9	15.2
1985	26	15.2
1986	15	15.2
1987	10	15.2
1988	22	15.2
1989	18	15.2
1990	5	9.6
1991	14	9.6
1992	3	9.6
1993	11	9.6
1994	10	9.6
1995	8	9.6
1996	15	9.6
1997	11	9.6

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

First to last qualifying date each year at Grootdam
Year	First date	Last date
1915	1915-01-19	1915-12-29
1916	1916-03-01	1916-12-17
1917	1917-02-19	1917-12-31
1918	1918-01-01	1918-12-02
1919	1919-02-15	1919-12-29
1920	1920-01-29	1920-12-18
1921	1921-02-10	1921-12-27
1925	1925-01-30	1925-12-05
1926	1926-01-26	1926-12-27
1930	1930-01-20	1930-12-14
1931	1931-01-15	1931-12-31
1932	1932-01-01	1932-12-25
1933	1933-02-12	1933-11-29
1934	1934-01-07	1934-12-29
1935	1935-02-05	1935-11-01
1936	1936-02-13	1936-12-10
1937	1937-01-22	1937-12-06
1938	1938-01-21	1938-11-09
1939	1939-01-29	1939-09-25
1940	1940-01-19	1940-11-08
1942	1942-01-27	1942-11-03
1943	1943-01-21	1943-12-31
1944	1944-01-13	1944-10-22
1945	1945-01-06	1945-10-04
1946	1946-01-08	1946-11-25
1947	1947-01-14	1947-12-23
1948	1948-01-28	1948-12-16
1949	1949-03-04	1949-12-10
1950	1950-01-05	1950-12-29
1951	1951-01-01	1951-10-26
1952	1952-02-11	1952-12-16
1953	1953-01-06	1953-12-28
1954	1954-02-07	1954-11-05
1955	1955-01-26	1955-11-28
1956	1956-01-16	1956-12-07
1957	1957-01-07	1957-12-31
1958	1958-01-13	1958-12-31
1959	1959-01-25	1959-12-03
1960	1960-01-17	1960-12-28
1961	1961-01-14	1961-12-15
1962	1962-01-18	1962-11-15
1963	1963-01-02	1963-12-08
1964	1964-01-19	1964-12-13
1965	1965-06-16	1965-11-16
1966	1966-01-19	1966-09-03
1967	1967-01-01	1967-10-30
1968	1968-03-08	1968-12-07
1969	1969-01-05	1969-10-19
1970	1970-02-01	1970-12-24
1971	1971-01-18	1971-11-19
1972	1972-01-09	1972-10-13
1973	1973-02-17	1973-12-22
1974	1974-01-10	1974-12-09
1975	1975-01-22	1975-12-22
1976	1976-01-05	1976-12-26
1977	1977-01-08	1977-11-30
1978	1978-03-02	1978-12-08
1979	1979-01-25	1979-11-18
1980	1980-02-06	1980-12-12
1981	1981-01-24	1981-12-22
1982	1982-01-23	1982-11-15
1983	1983-02-01	1983-12-20
1984	1984-01-11	1984-11-27
1985	1985-01-12	1985-12-19
1986	1986-01-02	1986-11-25
1987	1987-02-09	1987-10-18
1988	1988-01-14	1988-12-24
1989	1989-01-02	1989-12-23
1990	1990-02-08	1990-03-30
1991	1991-01-21	1991-12-11
1992	1992-02-27	1992-08-08
1993	1993-02-12	1993-12-28
1994	1994-01-08	1994-12-26
1995	1995-01-13	1995-12-16
1996	1996-01-14	1996-12-29
1997	1997-01-07	1997-11-29

Every Fixed Threshold

Fixed thresholds at Grootdam
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	76	26	1985	11
25 mm (0.98 in): Days with 25 mm or more rain	71	10	1974	4
50 mm (1.97 in): Days with 50 mm or more rain	17	2	1974	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1915.

Download the Data

Data for Grootdam 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).

Grootdam Threshold Days by Year (SF001215980)

Key Facts for Grootdam Thresholds

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

Every Fixed Threshold

Download the Data

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