Yellowstone Park Mammoth Threshold Days by Year (USC00489905)

13 fixed thresholds counted per year at Yellowstone Park Mammoth (USC00489905): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Yellowstone Park Mammoth Thresholds

Yellowstone Park Mammoth: days with a maximum temperature at or below 0 C (32 F) in 82 years, most in 1948 with 108.
Yellowstone Park Mammoth: nights with a minimum temperature at or below 0 C (32 F) in 82 years, most in 1959 with 234.
Yellowstone Park Mammoth: nights with a minimum temperature at or below -10 C (14 F) in 82 years, most in 1948 with 108.
Yellowstone Park Mammoth: days with 10 mm (0.39 in) or more of precipitation in 81 years, most in 1896 with 17.
13 fixed thresholds have at least one qualifying day at Yellowstone Park Mammoth.

Days at or above 30 C (86 F)

80 years with a qualifying day

Days per year at Yellowstone Park Mammoth with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 44 in 2022.

Days at or above 30 C (86 F) per year at Yellowstone Park Mammoth
Year	Days	Decade average
1896	6	6.5
1897	4	6.5
1898	12	6.5
1899	4	6.5
1900	17	10
1901	16	10
1902	1	10
1903	6	10
1942	10	8.9
1943	13	8.9
1945	9	8.9
1946	15	8.9
1947	2	8.9
1948	1	8.9
1949	12	8.9
1950	9	10.7
1951	10	10.7
1952	2	10.7
1953	5	10.7
1954	15	10.7
1955	25	10.7
1956	15	10.7
1957	6	10.7
1958	9	10.7
1959	11	10.7
1960	18	12.9
1961	23	12.9
1962	3	12.9
1963	18	12.9
1964	17	12.9
1965	4	12.9
1968	6	12.9
1969	14	12.9
1970	22	14.3
1972	6	14.3
1973	15	14.3
1974	19	14.3
1975	7	14.3
1976	10	14.3
1979	21	14.3
1980	6	11.6
1986	8	11.6
1987	5	11.6
1988	22	11.6
1989	17	11.6
1990	22	16.1
1991	21	16.1
1992	6	16.1
1994	16	16.1
1995	11	16.1
1996	18	16.1
1997	9	16.1
1998	27	16.1
1999	15	16.1
2000	26	23.9
2001	19	23.9
2002	19	23.9
2003	39	23.9
2004	15	23.9
2005	26	23.9
2006	32	23.9
2007	42	23.9
2008	14	23.9
2009	7	23.9
2010	8	18.5
2011	15	18.5
2012	20	18.5
2013	22	18.5
2014	10	18.5
2015	13	18.5
2016	27	18.5
2017	27	18.5
2018	22	18.5
2019	21	18.5
2020	19	28.5
2021	37	28.5
2022	44	28.5
2023	18	28.5
2024	25	28.5
2026	28	28.5

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

First to last qualifying date each year at Yellowstone Park Mammoth
Year	First date	Last date
1896	1896-07-05	1896-08-28
1897	1897-07-12	1897-08-24
1898	1898-06-18	1898-08-26
1899	1899-07-10	1899-07-20
1900	1900-06-21	1900-08-04
1901	1901-07-06	1901-08-15
1902	1902-07-24	1902-07-24
1903	1903-07-12	1903-08-21
1942	1942-07-04	1942-08-23
1943	1943-07-06	1943-08-14
1945	1945-07-21	1945-08-05
1946	1946-07-13	1946-08-22
1947	1947-07-07	1947-07-14
1948	1948-08-29	1948-08-29
1949	1949-07-15	1949-08-21
1950	1950-08-09	1950-09-07
1951	1951-07-14	1951-08-04
1952	1952-07-09	1952-07-30
1953	1953-08-07	1953-09-12
1954	1954-07-04	1954-08-31
1955	1955-06-22	1955-09-07
1956	1956-06-19	1956-09-19
1957	1957-07-10	1957-08-10
1958	1958-08-02	1958-08-17
1959	1959-06-12	1959-08-08
1960	1960-06-27	1960-08-13
1961	1961-06-20	1961-08-23
1962	1962-08-09	1962-08-16
1963	1963-07-03	1963-08-15
1964	1964-07-07	1964-08-18
1965	1965-07-16	1965-08-09
1968	1968-07-05	1968-07-30
1969	1969-08-02	1969-08-27
1970	1970-06-24	1970-08-26
1972	1972-07-29	1972-08-12
1973	1973-07-04	1973-08-20
1974	1974-06-16	1974-07-29
1975	1975-07-03	1975-08-07
1976	1976-07-06	1976-09-06
1979	1979-06-26	1979-09-09
1980	1980-07-23	1980-07-30
1986	1986-06-02	1986-08-28
1987	1987-06-03	1987-07-27
1988	1988-06-18	1988-09-04
1989	1989-07-04	1989-08-02
1990	1990-06-25	1990-09-15
1991	1991-07-05	1991-09-01
1992	1992-06-24	1992-08-20
1994	1994-06-21	1994-08-21
1995	1995-07-09	1995-09-03
1996	1996-07-03	1996-08-31
1997	1997-07-10	1997-09-01
1998	1998-07-14	1998-09-08
1999	1999-07-13	1999-08-28
2000	2000-06-06	2000-09-17
2001	2001-07-01	2001-09-05
2002	2002-06-27	2002-07-26
2003	2003-05-29	2003-09-05
2004	2004-07-13	2004-09-01
2005	2005-06-22	2005-08-30
2006	2006-06-29	2006-09-13
2007	2007-06-22	2007-09-12
2008	2008-06-30	2008-08-31
2009	2009-07-19	2009-08-23
2010	2010-06-29	2010-08-27
2011	2011-07-04	2011-08-29
2012	2012-06-25	2012-08-29
2013	2013-06-29	2013-09-02
2014	2014-07-04	2014-08-13
2015	2015-06-27	2015-08-26
2016	2016-06-08	2016-09-01
2017	2017-06-21	2017-09-05
2018	2018-07-06	2018-08-18
2019	2019-07-13	2019-09-06
2020	2020-07-18	2020-09-06
2021	2021-06-04	2021-09-09
2022	2022-07-07	2022-09-08
2023	2023-07-11	2023-08-18
2024	2024-06-24	2024-09-08
2026	2026-07-06	2026-08-22

Every Fixed Threshold

Fixed thresholds at Yellowstone Park Mammoth
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	80	44	2022	28
35 C (95 F): Days	13	8	2003	2
90 F (32.2 C): Days	62	24	2003	12
0 C (32 F): Ice days (max	82	108	1948	19
0 C (32 F): Frost days (min	82	234	1959	124
-10 C (14 F): Days with min	82	108	1948	28
-20 C (-4 F): Days with min	80	27	1949	2
-30 C (-22 F): Days with min	38	7	1972	2
10 mm (0.39 in): Days with 10 mm or more rain	81	17	1896	4
25 mm (0.98 in): Days with 25 mm or more rain	25	3	1944	1
50 mm (1.97 in): Days with 50 mm or more rain	1	1	2022	1
10 cm (3.9 in): Days with 10 cm or more snowfall	72	12	1946	2
25 cm (9.8 in): Days with 25 cm or more snowfall	13	1	1955	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1896.

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Data for Yellowstone Park Mammoth 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).

Yellowstone Park Mammoth Threshold Days by Year (USC00489905)

Key Facts for Yellowstone Park Mammoth Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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