Jefferson Threshold Days by Year (USC00134228)

19 fixed thresholds counted per year at Jefferson (USC00134228): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Jefferson Thresholds

Jefferson: days with 10 mm (0.39 in) or more of precipitation in 110 years, most in 2015 with 41.
Jefferson: days with 25 mm (0.98 in) or more of precipitation in 110 years, most in 1902 with 17.
Jefferson: nights with a minimum temperature at or below 0 C (32 F) in 108 years, most in 2022 with 172.
Jefferson: nights with a minimum temperature at or below -10 C (14 F) in 108 years, most in 2008 with 78.
19 fixed thresholds have at least one qualifying day at Jefferson.

Days at or above 30 C (86 F)

106 years with a qualifying day

Days per year at Jefferson with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 98 in 1988.

Days at or above 30 C (86 F) per year at Jefferson
Year	Days	Decade average
1911	89	49.9
1912	46	49.9
1914	68	49.9
1915	13	49.9
1916	54	49.9
1917	27	49.9
1918	56	49.9
1919	46	49.9
1920	44	38.7
1921	60	38.7
1922	36	38.7
1923	31	38.7
1924	15	38.7
1925	54	38.7
1926	38	38.7
1927	42	38.7
1929	28	38.7
1930	52	58.9
1931	65	58.9
1932	36	58.9
1933	62	58.9
1934	71	58.9
1935	43	58.9
1936	73	58.9
1937	65	58.9
1938	54	58.9
1939	68	58.9
1940	37	41.4
1941	55	41.4
1942	38	41.4
1943	44	41.4
1944	39	41.4
1945	29	41.4
1946	21	41.4
1947	59	41.4
1948	46	41.4
1949	46	41.4
1950	15	45.3
1951	16	45.3
1953	61	45.3
1954	56	45.3
1955	66	45.3
1956	63	45.3
1957	41	45.3
1958	30	45.3
1959	60	45.3
1960	46	38.7
1961	47	38.7
1962	48	38.7
1964	47	38.7
1967	21	38.7
1968	39	38.7
1969	23	38.7
1970	50	58.9
1971	47	58.9
1972	43	58.9
1973	52	58.9
1974	48	58.9
1975	72	58.9
1976	81	58.9
1977	78	58.9
1978	65	58.9
1979	53	58.9
1980	90	68.4
1981	59	68.4
1982	47	68.4
1983	84	68.4
1984	63	68.4
1985	62	68.4
1986	44	68.4
1987	80	68.4
1988	98	68.4
1989	57	68.4
1990	55	42
1991	67	42
1992	21	42
1993	22	42
1994	45	42
1995	49	42
1996	24	42
1997	50	42
1998	50	42
1999	37	42
2000	46	43.6
2001	55	43.6
2002	59	43.6
2003	50	43.6
2004	25	43.6
2005	54	43.6
2006	47	43.6
2007	64	43.6
2008	23	43.6
2009	13	43.6
2010	36	37.2
2011	38	37.2
2012	73	37.2
2013	43	37.2
2014	13	37.2
2015	20	37.2
2020	47	39.3
2021	48	39.3
2022	44	39.3
2023	32	39.3
2024	32	39.3
2025	37	39.3
2026	35	39.3

For each year, a bar from the first to the last day at Jefferson meeting 30 C (86 F).

First to last qualifying date each year at Jefferson
Year	First date	Last date
1911	1911-05-08	1911-09-27
1912	1912-05-19	1912-10-05
1914	1914-05-10	1914-09-06
1915	1915-04-28	1915-08-07
1916	1916-05-07	1916-09-06
1917	1917-05-17	1917-09-05
1918	1918-05-03	1918-09-01
1919	1919-05-28	1919-09-20
1920	1920-05-22	1920-10-10
1921	1921-05-20	1921-08-31
1922	1922-06-07	1922-10-04
1923	1923-06-01	1923-09-05
1924	1924-05-05	1924-08-30
1925	1925-04-22	1925-09-19
1926	1926-04-30	1926-09-21
1927	1927-04-26	1927-10-25
1929	1929-04-04	1929-09-03
1930	1930-04-10	1930-10-10
1931	1931-04-08	1931-09-20
1932	1932-05-13	1932-09-18
1933	1933-05-18	1933-09-25
1934	1934-05-06	1934-10-08
1935	1935-06-14	1935-09-18
1936	1936-05-16	1936-09-22
1937	1937-06-19	1937-10-29
1938	1938-06-05	1938-10-15
1939	1939-04-24	1939-09-28
1940	1940-05-12	1940-09-22
1941	1941-05-14	1941-09-21
1942	1942-05-28	1942-09-16
1943	1943-05-28	1943-08-31
1944	1944-05-14	1944-09-03
1945	1945-05-20	1945-09-23
1946	1946-06-07	1946-08-20
1947	1947-06-09	1947-10-21
1948	1948-04-18	1948-09-19
1949	1949-04-25	1949-08-26
1950	1950-05-23	1950-09-18
1951	1951-07-07	1951-08-31
1953	1953-05-25	1953-10-15
1954	1954-04-14	1954-09-27
1955	1955-05-06	1955-09-18
1956	1956-05-12	1956-10-12
1957	1957-06-05	1957-09-01
1958	1958-05-11	1958-10-04
1959	1959-05-01	1959-09-14
1960	1960-04-22	1960-10-11
1961	1961-05-31	1961-09-10
1962	1962-05-05	1962-10-10
1964	1964-05-17	1964-09-09
1967	1967-04-16	1967-08-26
1968	1968-05-02	1968-10-15
1969	1969-05-27	1969-10-04
1970	1970-04-27	1970-09-21
1971	1971-06-03	1971-10-01
1972	1972-05-21	1972-09-20
1973	1973-05-18	1973-09-04
1974	1974-06-03	1974-09-26
1975	1975-05-18	1975-10-13
1976	1976-05-20	1976-10-03
1977	1977-04-09	1977-09-08
1978	1978-05-19	1978-09-18
1979	1979-05-17	1979-09-27
1980	1980-04-20	1980-10-09
1981	1981-04-02	1981-09-30
1982	1982-05-04	1982-09-12
1983	1983-05-27	1983-10-02
1984	1984-05-17	1984-09-20
1985	1985-04-17	1985-09-20
1986	1986-03-29	1986-09-26
1987	1987-04-17	1987-09-26
1988	1988-05-05	1988-09-18
1989	1989-04-21	1989-09-01
1990	1990-05-07	1990-10-05
1991	1991-04-05	1991-09-14
1992	1992-04-30	1992-08-24
1993	1993-05-27	1993-10-07
1994	1994-04-18	1994-10-01
1995	1995-06-07	1995-09-14
1996	1996-05-17	1996-09-04
1997	1997-05-18	1997-10-07
1998	1998-05-18	1998-09-30
1999	1999-06-06	1999-09-24
2000	2000-05-08	2000-09-19
2001	2001-04-27	2001-09-06
2002	2002-04-16	2002-10-01
2003	2003-04-02	2003-10-21
2004	2004-04-17	2004-09-20
2005	2005-06-07	2005-10-05
2006	2006-04-14	2006-10-04
2007	2007-04-30	2007-10-07
2008	2008-05-26	2008-09-02
2009	2009-04-25	2009-08-13
2010	2010-04-02	2010-10-10
2011	2011-04-11	2011-10-05
2012	2012-04-02	2012-09-12
2013	2013-05-15	2013-09-28
2014	2014-05-08	2014-09-05
2015	2015-06-09	2015-10-12
2020	2020-06-02	2020-10-10
2021	2021-04-27	2021-09-29
2022	2022-05-10	2022-09-21
2023	2023-04-13	2023-10-04
2024	2024-06-04	2024-10-06
2025	2025-05-11	2025-10-05
2026	2026-03-22	2026-09-07

Every Fixed Threshold

Fixed thresholds at Jefferson
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	106	98	1988	35
35 C (95 F): Days	89	39	1936	2
40 C (104 F): Days	8	10	1936	4
90 F (32.2 C): Days	106	69	1911	11
100 F (37.8 C): Days	32	18	1936	1
110 F (43.3 C): Days	1	1	1911	1
0 C (32 F): Ice days (max	106	86	2010	25
0 C (32 F): Frost days (min	108	172	2022	77
-10 C (14 F): Days with min	108	78	2008	27
-20 C (-4 F): Days with min	107	32	1936	7
-30 C (-22 F): Days with min	24	5	1936	2
20 C (68 F): Tropical nights (min	107	47	1983	23
25 C (77 F): Days with min	35	8	1930	1
10 mm (0.39 in): Days with 10 mm or more rain	110	41	2015	19
25 mm (0.98 in): Days with 25 mm or more rain	110	17	1902	8
50 mm (1.97 in): Days with 50 mm or more rain	84	6	1902	2
100 mm (3.94 in): Days with 100 mm or more rain	15	2	2006	1
10 cm (3.9 in): Days with 10 cm or more snowfall	80	6	1969	2
25 cm (9.8 in): Days with 25 cm or more snowfall	7	1	1923	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1911.

Download the Data

Data for Jefferson 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 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Jefferson Threshold Days by Year (USC00134228)

Key Facts for Jefferson Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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