San Jon Threshold Days by Year (USC00297867)

18 fixed thresholds counted per year at San Jon (USC00297867): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for San Jon Thresholds

San Jon: days with 10 mm (0.39 in) or more of precipitation in 108 years, most in 1960 with 28.
San Jon: days with 25 mm (0.98 in) or more of precipitation in 103 years, most in 1991 with 15.
San Jon: nights with a minimum temperature at or below 0 C (32 F) in 98 years, most in 1944 with 140.
San Jon: nights with a minimum temperature at or above 20 C (68 F) in 98 years, most in 2011 with 64.
18 fixed thresholds have at least one qualifying day at San Jon.

Days at or above 30 C (86 F)

97 years with a qualifying day

Days per year at San Jon with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 143 in 2012.

Days at or above 30 C (86 F) per year at San Jon
Year	Days	Decade average
1908	111	109
1909	107	109
1910	115	101.9
1911	118	101.9
1912	96	101.9
1913	104	101.9
1915	84	101.9
1916	107	101.9
1917	111	101.9
1918	80	101.9
1923	85	92.7
1924	98	92.7
1927	95	92.7
1931	104	107.6
1932	99	107.6
1933	113	107.6
1934	135	107.6
1935	105	107.6
1936	100	107.6
1939	97	107.6
1940	118	105.7
1941	67	105.7
1942	85	105.7
1943	121	105.7
1944	95	105.7
1945	119	105.7
1946	107	105.7
1947	133	105.7
1948	130	105.7
1949	82	105.7
1950	106	117.6
1951	120	117.6
1952	114	117.6
1953	129	117.6
1954	131	117.6
1955	111	117.6
1956	142	117.6
1957	98	117.6
1958	105	117.6
1959	120	117.6
1960	104	117.8
1962	137	117.8
1963	140	117.8
1964	123	117.8
1965	108	117.8
1966	115	117.8
1967	111	117.8
1968	116	117.8
1969	106	117.8
1970	109	113.7
1971	106	113.7
1972	107	113.7
1973	113	113.7
1974	124	113.7
1975	105	113.7
1976	112	113.7
1977	124	113.7
1978	118	113.7
1979	119	113.7
1980	120	104
1981	105	104
1982	97	104
1983	114	104
1984	111	104
1985	115	104
1986	93	104
1987	89	104
1988	82	104
1989	114	104
1990	112	107.1
1991	95	107.1
1992	90	107.1
1993	110	107.1
1994	116	107.1
1995	108	107.1
1996	110	107.1
1997	101	107.1
1998	128	107.1
1999	101	107.1
2000	133	113.6
2001	135	113.6
2002	121	113.6
2004	94	113.6
2005	105	113.6
2006	117	113.6
2007	109	113.6
2008	102	113.6
2009	106	113.6
2010	112	126.5
2011	131	126.5
2012	143	126.5
2013	124	126.5
2014	125	126.5
2017	125	126.5
2018	143	126.5
2019	109	126.5
2020	132	132

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

First to last qualifying date each year at San Jon
Year	First date	Last date
1908	1908-03-16	1908-10-15
1909	1909-04-16	1909-10-16
1910	1910-03-25	1910-10-12
1911	1911-04-22	1911-10-05
1912	1912-04-30	1912-09-24
1913	1913-04-17	1913-09-23
1915	1915-04-28	1915-11-05
1916	1916-03-13	1916-11-03
1917	1917-04-22	1917-10-16
1918	1918-05-07	1918-10-08
1923	1923-05-10	1923-09-28
1924	1924-05-04	1924-10-04
1927	1927-04-03	1927-10-05
1931	1931-05-14	1931-10-10
1932	1932-04-02	1932-09-21
1933	1933-05-11	1933-10-04
1934	1934-04-10	1934-10-15
1935	1935-04-14	1935-10-13
1936	1936-04-12	1936-10-19
1939	1939-04-22	1939-10-06
1940	1940-04-01	1940-10-19
1941	1941-05-08	1941-10-13
1942	1942-04-04	1942-10-08
1943	1943-04-03	1943-10-18
1944	1944-05-07	1944-09-22
1945	1945-04-09	1945-09-27
1946	1946-03-30	1946-09-27
1947	1947-04-21	1947-10-21
1948	1948-04-10	1948-10-13
1949	1949-05-02	1949-10-08
1950	1950-04-03	1950-10-31
1951	1951-04-24	1951-10-12
1952	1952-04-07	1952-10-03
1953	1953-04-21	1953-10-17
1954	1954-04-04	1954-10-13
1955	1955-04-25	1955-10-20
1956	1956-04-26	1956-10-11
1957	1957-04-18	1957-10-05
1958	1958-05-06	1958-10-19
1959	1959-04-06	1959-10-25
1960	1960-04-10	1960-10-10
1962	1962-04-14	1962-10-14
1963	1963-03-28	1963-10-15
1964	1964-04-19	1964-10-30
1965	1965-04-17	1965-10-15
1966	1966-03-31	1966-10-02
1967	1967-03-29	1967-10-19
1968	1968-05-02	1968-10-30
1969	1969-04-22	1969-10-09
1970	1970-05-10	1970-10-06
1971	1971-03-26	1971-10-15
1972	1972-03-11	1972-10-16
1973	1973-05-10	1973-11-12
1974	1974-03-17	1974-10-05
1975	1975-04-25	1975-10-20
1976	1976-04-10	1976-10-11
1977	1977-04-08	1977-10-01
1978	1978-04-01	1978-10-12
1979	1979-04-15	1979-10-26
1980	1980-04-19	1980-11-08
1981	1981-04-10	1981-09-30
1982	1982-04-11	1982-10-05
1983	1983-05-05	1983-10-10
1984	1984-04-17	1984-10-02
1985	1985-04-15	1985-10-07
1986	1986-04-07	1986-09-22
1987	1987-04-17	1987-10-08
1988	1988-05-13	1988-10-17
1989	1989-03-10	1989-10-14
1990	1990-04-16	1990-10-31
1991	1991-04-07	1991-10-18
1992	1992-04-10	1992-10-13
1993	1993-04-22	1993-10-06
1994	1994-04-18	1994-10-04
1995	1995-03-21	1995-10-21
1996	1996-04-10	1996-10-14
1997	1997-05-07	1997-10-05
1998	1998-04-24	1998-10-14
1999	1999-05-08	1999-10-15
2000	2000-04-14	2000-10-04
2001	2001-04-19	2001-10-19
2002	2002-04-01	2002-10-11
2004	2004-03-19	2004-09-18
2005	2005-05-10	2005-10-04
2006	2006-02-28	2006-11-09
2007	2007-03-18	2007-10-20
2008	2008-04-15	2008-10-31
2009	2009-04-23	2009-10-19
2010	2010-03-30	2010-10-15
2011	2011-03-17	2011-10-04
2012	2012-03-24	2012-10-23
2013	2013-04-22	2013-10-03
2014	2014-04-09	2014-10-26
2017	2017-03-19	2017-10-17
2018	2018-03-23	2018-10-29
2019	2019-03-28	2019-10-14
2020	2020-04-08	2020-10-22

Every Fixed Threshold

Fixed thresholds at San Jon
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	97	143	2012	132
35 C (95 F): Days	97	88	2020	88
40 C (104 F): Days	61	17	2020	17
90 F (32.2 C): Days	97	121	2018	114
100 F (37.8 C): Days	95	39	2011	35
110 F (43.3 C): Days	3	3	2020	3
0 C (32 F): Ice days (max	92	20	1918	4
0 C (32 F): Frost days (min	98	140	1944	106
-10 C (14 F): Days with min	97	35	1918	4
-20 C (-4 F): Days with min	38	8	1918	1
20 C (68 F): Tropical nights (min	98	64	2011	41
25 C (77 F): Days with min	29	7	1953	7
10 mm (0.39 in): Days with 10 mm or more rain	108	28	1960	11
25 mm (0.98 in): Days with 25 mm or more rain	103	15	1991	2
50 mm (1.97 in): Days with 50 mm or more rain	41	3	1972	1
100 mm (3.94 in): Days with 100 mm or more rain	1	1	1911	1
10 cm (3.9 in): Days with 10 cm or more snowfall	67	5	1983	1
25 cm (9.8 in): Days with 25 cm or more snowfall	17	1	1912	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 San Jon 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).

San Jon Threshold Days by Year (USC00297867)

Key Facts for San Jon Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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