West Swan Threshold Days by Year (ASN00009163)

4 fixed thresholds counted per year at West Swan (ASN00009163): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for West Swan Thresholds

West Swan: days with 10 mm (0.39 in) or more of precipitation in 77 years, most in 1926 with 48.
West Swan: days with 25 mm (0.98 in) or more of precipitation in 77 years, most in 1920 with 12.
West Swan: days with 50 mm (1.97 in) or more of precipitation in 27 years, most in 1945 with 3.
West Swan: days with 100 mm (3.94 in) or more of precipitation in 1 years, most in 2001 with 1.
4 fixed thresholds have at least one qualifying day at West Swan.

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

77 years with a qualifying day

Days per year at West Swan with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 48 in 1926.

Days with 10 mm (0.39 in) or more of precipitation per year at West Swan
Year	Days	Decade average
1918	33	27.5
1919	22	27.5
1920	39	32.6
1921	32	32.6
1922	21	32.6
1923	42	32.6
1924	27	32.6
1925	25	32.6
1926	48	32.6
1927	36	32.6
1928	28	32.6
1929	28	32.6
1930	27	29
1931	37	29
1932	28	29
1933	26	29
1934	35	29
1935	23	29
1936	25	29
1937	25	29
1938	27	29
1939	37	29
1940	13	26.8
1941	31	26.8
1942	40	26.8
1943	22	26.8
1944	18	26.8
1945	34	26.8
1946	44	26.8
1947	28	26.8
1948	17	26.8
1949	21	26.8
1950	27	30.2
1951	30	30.2
1952	28	30.2
1953	29	30.2
1954	24	30.2
1955	43	30.2
1965	31	24.4
1966	22	24.4
1967	27	24.4
1968	28	24.4
1969	14	24.4
1970	27	24.7
1971	22	24.7
1972	18	24.7
1973	37	24.7
1974	38	24.7
1975	22	24.7
1976	24	24.7
1977	14	24.7
1978	28	24.7
1979	17	24.7
1980	26	24
1981	28	24
1982	25	24
1983	26	24
1984	24	24
1985	17	24
1986	30	24
1987	20	24
1988	22	24
1989	22	24
1990	24	24.5
1991	37	24.5
1992	23	24.5
1993	23	24.5
1994	17	24.5
1995	26	24.5
1996	29	24.5
1997	23	24.5
1998	20	24.5
1999	23	24.5
2000	28	22.8
2001	19	22.8
2002	17	22.8
2003	27	22.8

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

First to last qualifying date each year at West Swan
Year	First date	Last date
1918	1918-03-27	1918-10-28
1919	1919-02-24	1919-12-10
1920	1920-03-29	1920-10-10
1921	1921-03-22	1921-10-15
1922	1922-04-27	1922-09-25
1923	1923-01-20	1923-12-16
1924	1924-05-04	1924-11-10
1925	1925-05-05	1925-11-09
1926	1926-03-11	1926-10-22
1927	1927-03-13	1927-10-29
1928	1928-05-26	1928-10-21
1929	1929-01-02	1929-10-29
1930	1930-04-15	1930-09-07
1931	1931-04-12	1931-10-01
1932	1932-04-05	1932-10-29
1933	1933-04-09	1933-10-19
1934	1934-03-08	1934-11-06
1935	1935-04-03	1935-10-26
1936	1936-04-15	1936-12-18
1937	1937-04-19	1937-11-24
1938	1938-03-16	1938-11-02
1939	1939-02-15	1939-10-27
1940	1940-05-14	1940-10-21
1941	1941-04-13	1941-10-06
1942	1942-03-01	1942-12-21
1943	1943-01-31	1943-09-20
1944	1944-04-30	1944-12-07
1945	1945-05-04	1945-11-13
1946	1946-03-21	1946-11-13
1947	1947-03-06	1947-10-25
1948	1948-06-05	1948-11-15
1949	1949-04-29	1949-11-14
1950	1950-05-05	1950-11-08
1951	1951-02-23	1951-12-04
1952	1952-03-29	1952-12-18
1953	1953-02-02	1953-10-27
1954	1954-04-23	1954-11-11
1955	1955-02-15	1955-10-21
1965	1965-04-12	1965-11-06
1966	1966-05-06	1966-12-27
1967	1967-04-12	1967-12-09
1968	1968-02-03	1968-10-15
1969	1969-04-08	1969-11-03
1970	1970-02-17	1970-10-04
1971	1971-03-28	1971-10-21
1972	1972-05-31	1972-10-08
1973	1973-01-18	1973-10-24
1974	1974-02-03	1974-11-19
1975	1975-05-05	1975-11-16
1976	1976-01-07	1976-11-11
1977	1977-05-16	1977-10-30
1978	1978-02-24	1978-10-02
1979	1979-04-15	1979-11-07
1980	1980-02-11	1980-10-22
1981	1981-02-18	1981-11-26
1982	1982-01-21	1982-10-25
1983	1983-04-01	1983-12-31
1984	1984-03-04	1984-12-28
1985	1985-04-09	1985-09-22
1986	1986-02-21	1986-11-30
1987	1987-04-25	1987-12-24
1988	1988-04-28	1988-11-07
1989	1989-04-24	1989-10-02
1990	1990-01-29	1990-10-30
1991	1991-04-10	1991-12-25
1992	1992-02-09	1992-11-20
1993	1993-02-06	1993-10-27
1994	1994-05-23	1994-09-11
1995	1995-05-10	1995-11-08
1996	1996-05-31	1996-11-16
1997	1997-03-30	1997-10-10
1998	1998-03-10	1998-12-15
1999	1999-01-23	1999-10-14
2000	2000-01-15	2000-09-06
2001	2001-05-06	2001-11-19
2002	2002-04-17	2002-11-01
2003	2003-02-02	2003-10-27

Every Fixed Threshold

Fixed thresholds at West Swan
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	77	48	1926	27
25 mm (0.98 in): Days with 25 mm or more rain	77	12	1920	7
50 mm (1.97 in): Days with 50 mm or more rain	27	3	1945	1
100 mm (3.94 in): Days with 100 mm or more rain	1	1	2001	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1918.

Download the Data

Data for West Swan 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).

West Swan Threshold Days by Year (ASN00009163)

Key Facts for West Swan Thresholds

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

Every Fixed Threshold

Download the Data

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