Swan Island Lighthouse Threshold Days by Year (ASN00092037)

3 fixed thresholds counted per year at Swan Island Lighthouse (ASN00092037): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Swan Island Lighthouse Thresholds

Swan Island Lighthouse: days with 10 mm (0.39 in) or more of precipitation in 95 years, most in 1939 with 37.
Swan Island Lighthouse: days with 25 mm (0.98 in) or more of precipitation in 90 years, most in 1939 with 9.
Swan Island Lighthouse: days with 50 mm (1.97 in) or more of precipitation in 23 years, most in 1964 with 2.
3 fixed thresholds have at least one qualifying day at Swan Island Lighthouse.

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

95 years with a qualifying day

Days per year at Swan Island Lighthouse with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 37 in 1939.

Days with 10 mm (0.39 in) or more of precipitation per year at Swan Island Lighthouse
Year	Days	Decade average
1908	4	11
1909	18	11
1910	24	18.1
1911	20	18.1
1912	17	18.1
1913	11	18.1
1914	16	18.1
1915	12	18.1
1916	28	18.1
1917	22	18.1
1918	18	18.1
1919	13	18.1
1920	16	16.2
1921	20	16.2
1922	17	16.2
1923	18	16.2
1924	16	16.2
1925	8	16.2
1926	16	16.2
1927	9	16.2
1928	24	16.2
1929	18	16.2
1930	21	21
1931	21	21
1932	20	21
1933	12	21
1934	24	21
1935	18	21
1936	21	21
1937	21	21
1938	15	21
1939	37	21
1940	9	15.2
1941	6	15.2
1942	20	15.2
1943	7	15.2
1944	12	15.2
1945	17	15.2
1946	23	15.2
1947	26	15.2
1948	11	15.2
1949	21	15.2
1951	7	18.3
1952	26	18.3
1953	18	18.3
1954	12	18.3
1955	31	18.3
1956	22	18.3
1957	13	18.3
1958	23	18.3
1959	13	18.3
1960	21	16.4
1961	12	16.4
1962	24	16.4
1963	11	16.4
1964	23	16.4
1965	14	16.4
1966	14	16.4
1967	11	16.4
1968	17	16.4
1969	17	16.4
1970	31	18.8
1971	29	18.8
1972	16	18.8
1973	24	18.8
1974	16	18.8
1975	16	18.8
1976	17	18.8
1977	9	18.8
1978	19	18.8
1979	11	18.8
1980	16	15.8
1981	11	15.8
1982	11	15.8
1983	18	15.8
1984	18	15.8
1985	21	15.8
1986	14	15.8
1987	14	15.8
1988	16	15.8
1989	19	15.8
1990	11	14.1
1991	17	14.1
1992	17	14.1
1993	16	14.1
1994	11	14.1
1995	13	14.1
1996	14	14.1
1997	10	14.1
1998	18	14.1
1999	14	14.1
2000	15	17.5
2001	20	17.5
2002	16	17.5
2003	19	17.5

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

First to last qualifying date each year at Swan Island Lighthouse
Year	First date	Last date
1908	1908-03-15	1908-07-21
1909	1909-01-04	1909-12-22
1910	1910-01-15	1910-12-23
1911	1911-01-18	1911-12-05
1912	1912-04-07	1912-12-23
1913	1913-03-10	1913-10-15
1914	1914-01-28	1914-12-27
1915	1915-03-16	1915-09-15
1916	1916-01-04	1916-12-21
1917	1917-01-22	1917-11-15
1918	1918-01-15	1918-10-25
1919	1919-01-07	1919-12-28
1920	1920-02-29	1920-11-05
1921	1921-01-02	1921-12-24
1922	1922-01-24	1922-12-26
1923	1923-02-28	1923-12-15
1924	1924-01-26	1924-11-12
1925	1925-01-13	1925-10-12
1926	1926-04-11	1926-12-17
1927	1927-01-06	1927-12-04
1928	1928-01-24	1928-12-23
1929	1929-02-15	1929-12-28
1930	1930-02-20	1930-12-25
1931	1931-02-15	1931-11-21
1932	1932-03-07	1932-12-08
1933	1933-01-25	1933-12-15
1934	1934-01-09	1934-12-16
1935	1935-01-05	1935-09-15
1936	1936-01-31	1936-12-12
1937	1937-01-02	1937-12-26
1938	1938-02-05	1938-12-10
1939	1939-02-17	1939-12-23
1940	1940-01-19	1940-12-28
1941	1941-01-26	1941-11-19
1942	1942-01-25	1942-12-19
1943	1943-04-19	1943-11-21
1944	1944-01-04	1944-12-10
1945	1945-01-31	1945-12-28
1946	1946-01-18	1946-12-27
1947	1947-02-04	1947-12-31
1948	1948-01-13	1948-10-22
1949	1949-01-01	1949-12-21
1951	1951-04-21	1951-12-09
1952	1952-02-22	1952-11-27
1953	1953-01-06	1953-12-07
1954	1954-02-01	1954-12-12
1955	1955-01-29	1955-12-27
1956	1956-01-01	1956-10-23
1957	1957-03-10	1957-12-26
1958	1958-03-24	1958-12-18
1959	1959-01-26	1959-11-30
1960	1960-03-08	1960-11-13
1961	1961-04-08	1961-12-16
1962	1962-01-18	1962-12-10
1963	1963-01-28	1963-10-29
1964	1964-02-08	1964-12-24
1965	1965-01-19	1965-12-02
1966	1966-02-24	1966-12-16
1967	1967-07-01	1967-12-13
1968	1968-03-05	1968-12-24
1969	1969-01-15	1969-12-30
1970	1970-01-02	1970-12-31
1971	1971-02-01	1971-11-11
1972	1972-01-01	1972-11-25
1973	1973-01-13	1973-12-25
1974	1974-02-06	1974-12-26
1975	1975-01-10	1975-12-15
1976	1976-02-25	1976-12-24
1977	1977-02-19	1977-11-29
1978	1978-01-07	1978-12-27
1979	1979-01-21	1979-10-24
1980	1980-01-13	1980-12-14
1981	1981-01-10	1981-12-28
1982	1982-03-28	1982-12-09
1983	1983-03-09	1983-12-01
1984	1984-01-16	1984-12-15
1985	1985-02-18	1985-12-22
1986	1986-01-02	1986-12-17
1987	1987-01-01	1987-12-02
1988	1988-03-12	1988-12-04
1989	1989-03-11	1989-12-20
1990	1990-03-11	1990-12-20
1991	1991-01-05	1991-12-19
1992	1992-01-01	1992-11-22
1993	1993-01-17	1993-12-27
1994	1994-02-28	1994-12-20
1995	1995-01-06	1995-12-05
1996	1996-01-02	1996-11-14
1997	1997-01-16	1997-11-01
1998	1998-01-26	1998-12-28
1999	1999-01-29	1999-12-28
2000	2000-01-04	2000-12-23
2001	2001-01-18	2001-12-03
2002	2002-01-02	2002-11-26
2003	2003-01-27	2003-12-22

Every Fixed Threshold

Fixed thresholds at Swan Island Lighthouse
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	95	37	1939	19
25 mm (0.98 in): Days with 25 mm or more rain	90	9	1939	5
50 mm (1.97 in): Days with 50 mm or more rain	23	2	1964	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1908.

Download the Data

Data for Swan Island Lighthouse 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 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Swan Island Lighthouse Threshold Days by Year (ASN00092037)

Key Facts for Swan Island Lighthouse Thresholds

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

Every Fixed Threshold

Download the Data

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