San Marcos Threshold Days by Year (USC00417983)

17 fixed thresholds counted per year at San Marcos (USC00417983): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for San Marcos Thresholds

San Marcos: days with 10 mm (0.39 in) or more of precipitation in 109 years, most in 1973 with 40.
San Marcos: days with 25 mm (0.98 in) or more of precipitation in 109 years, most in 2004 with 19.
San Marcos: days with a maximum temperature at or above 30 C (86 F) in 104 years, most in 2025 with 193.
San Marcos: days with a maximum temperature at or above 35 C (95 F) in 104 years, most in 2022 with 112.
17 fixed thresholds have at least one qualifying day at San Marcos.

Days at or above 30 C (86 F)

104 years with a qualifying day

Days per year at San Marcos with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 193 in 2025.

Days at or above 30 C (86 F) per year at San Marcos
Year	Days	Decade average
1902	140	134
1906	124	134
1908	130	134
1909	142	134
1910	143	141.4
1911	147	141.4
1912	132	141.4
1913	117	141.4
1914	119	141.4
1915	136	141.4
1916	158	141.4
1917	167	141.4
1918	154	141.4
1921	136	167
1922	183	167
1923	167	167
1924	175	167
1926	151	167
1927	178	167
1928	174	167
1929	172	167
1930	147	165.9
1931	164	165.9
1932	152	165.9
1933	180	165.9
1934	174	165.9
1935	155	165.9
1936	150	165.9
1938	184	165.9
1939	187	165.9
1940	162	172
1941	163	172
1942	174	172
1943	192	172
1944	157	172
1946	167	172
1947	173	172
1948	190	172
1949	170	172
1950	186	160.1
1951	180	160.1
1952	151	160.1
1953	159	160.1
1954	143	160.1
1955	192	160.1
1958	129	160.1
1959	141	160.1
1960	143	141.7
1961	136	141.7
1962	154	141.7
1963	178	141.7
1964	138	141.7
1965	122	141.7
1966	131	141.7
1968	130	141.7
1969	143	141.7
1970	133	140.2
1971	153	140.2
1972	167	140.2
1973	140	140.2
1975	140	140.2
1976	110	140.2
1977	139	140.2
1978	144	140.2
1979	136	140.2
1980	148	151
1981	141	151
1983	134	151
1986	147	151
1987	152	151
1988	169	151
1989	166	151
1990	155	154
1991	157	154
1992	141	154
1994	143	154
1995	154	154
1996	168	154
1997	143	154
1998	151	154
1999	174	154
2000	162	146.2
2001	124	146.2
2002	149	146.2
2003	137	146.2
2004	134	146.2
2005	149	146.2
2006	175	146.2
2007	128	146.2
2009	158	146.2
2012	161	153.1
2013	152	153.1
2014	166	153.1
2015	146	153.1
2016	143	153.1
2017	154	153.1
2018	150	153.1
2019	153	153.1
2020	164	170.3
2022	183	170.3
2023	162	170.3
2024	178	170.3
2025	193	170.3
2026	142	170.3

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

First to last qualifying date each year at San Marcos
Year	First date	Last date
1902	1902-03-04	1902-10-14
1906	1906-03-27	1906-10-18
1908	1908-03-15	1908-10-21
1909	1909-01-28	1909-10-17
1910	1910-04-28	1910-10-17
1911	1911-03-07	1911-11-11
1912	1912-04-21	1912-10-11
1913	1913-03-30	1913-10-10
1914	1914-04-14	1914-10-11
1915	1915-05-12	1915-11-10
1916	1916-02-28	1916-11-07
1917	1917-01-29	1917-10-28
1918	1918-01-25	1918-10-08
1921	1921-03-14	1921-12-26
1922	1922-02-03	1922-12-02
1923	1923-01-07	1923-10-17
1924	1924-02-14	1924-12-14
1926	1926-02-13	1926-10-28
1927	1927-02-22	1927-11-29
1928	1928-03-11	1928-12-04
1929	1929-03-23	1929-10-28
1930	1930-02-22	1930-11-17
1931	1931-04-01	1931-11-15
1932	1932-02-09	1932-10-24
1933	1933-03-07	1933-12-21
1934	1934-03-22	1934-11-10
1935	1935-01-10	1935-11-10
1936	1936-01-16	1936-11-02
1938	1938-01-17	1938-11-17
1939	1939-03-10	1939-11-10
1940	1940-02-27	1940-10-27
1941	1941-03-31	1941-10-26
1942	1942-03-11	1942-12-25
1943	1943-01-23	1943-11-09
1944	1944-01-26	1944-11-01
1946	1946-03-02	1946-12-02
1947	1947-03-23	1947-11-06
1948	1948-02-19	1948-12-14
1949	1949-01-04	1949-11-30
1950	1950-02-26	1950-11-20
1951	1951-03-07	1951-11-16
1952	1952-03-01	1952-11-02
1953	1953-03-02	1953-10-22
1954	1954-02-11	1954-10-27
1955	1955-01-04	1955-12-26
1958	1958-04-04	1958-10-10
1959	1959-02-18	1959-10-27
1960	1960-02-10	1960-11-03
1961	1961-03-28	1961-11-02
1962	1962-02-10	1962-11-12
1963	1963-01-11	1963-11-07
1964	1964-04-04	1964-10-18
1965	1965-05-25	1965-11-25
1966	1966-04-01	1966-10-14
1968	1968-04-28	1968-11-01
1969	1969-04-06	1969-11-09
1970	1970-04-13	1970-11-23
1971	1971-01-26	1971-10-30
1972	1972-01-24	1972-11-01
1973	1973-04-03	1973-12-13
1975	1975-01-27	1975-11-10
1976	1976-03-21	1976-10-03
1977	1977-04-04	1977-11-01
1978	1978-03-01	1978-11-03
1979	1979-05-09	1979-10-30
1980	1980-02-20	1980-11-10
1981	1981-03-31	1981-10-18
1983	1983-04-28	1983-11-22
1986	1986-02-19	1986-11-19
1987	1987-04-11	1987-12-11
1988	1988-03-11	1988-11-14
1989	1989-03-13	1989-11-08
1990	1990-04-22	1990-10-20
1991	1991-03-04	1991-10-27
1992	1992-04-28	1992-11-01
1994	1994-03-05	1994-10-24
1995	1995-03-21	1995-11-11
1996	1996-02-20	1996-11-06
1997	1997-03-21	1997-10-31
1998	1998-04-24	1998-10-16
1999	1999-02-07	1999-11-15
2000	2000-03-09	2000-10-16
2001	2001-04-15	2001-10-24
2002	2002-04-08	2002-11-10
2003	2003-04-16	2003-10-31
2004	2004-05-10	2004-10-30
2005	2005-03-30	2005-11-27
2006	2006-03-01	2006-11-09
2007	2007-05-07	2007-11-21
2009	2009-02-23	2009-10-14
2012	2012-02-24	2012-11-06
2013	2013-03-05	2013-11-18
2014	2014-03-29	2014-10-28
2015	2015-04-08	2015-11-05
2016	2016-03-15	2016-11-04
2017	2017-02-08	2017-11-07
2018	2018-03-11	2018-10-15
2019	2019-03-10	2019-10-24
2020	2020-03-12	2020-10-23
2022	2022-03-26	2022-10-24
2023	2023-02-22	2023-10-28
2024	2024-02-22	2024-12-30
2025	2025-02-08	2025-11-19
2026	2026-01-02	2026-10-01

Every Fixed Threshold

Fixed thresholds at San Marcos
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	104	193	2025	142
35 C (95 F): Days	104	112	2022	63
40 C (104 F): Days	48	45	2023	4
90 F (32.2 C): Days	104	161	1948	98
100 F (37.8 C): Days	92	80	1924	26
110 F (43.3 C): Days	4	2	2000	2
0 C (32 F): Ice days (max	30	5	1951	2
0 C (32 F): Frost days (min	98	49	1951	11
-10 C (14 F): Days with min	18	8	1983	3
20 C (68 F): Tropical nights (min	98	183	1927	123
25 C (77 F): Days with min	70	55	2023	42
10 mm (0.39 in): Days with 10 mm or more rain	109	40	1973	20
25 mm (0.98 in): Days with 25 mm or more rain	109	19	2004	9
50 mm (1.97 in): Days with 50 mm or more rain	99	9	1921	1
100 mm (3.94 in): Days with 100 mm or more rain	43	3	1921	1
200 mm (7.87 in): Days with 200 mm or more rain	4	2	1913	1
10 cm (3.9 in): Days with 10 cm or more snowfall	6	2	1929	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1902.

Download the Data

Data for San Marcos 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 2026-10-14. Last revised 14 October 2026 (2026-10-14).

San Marcos Threshold Days by Year (USC00417983)

Key Facts for San Marcos Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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