Copperhill Threshold Days by Year (USC00402024)

15 fixed thresholds counted per year at Copperhill (USC00402024): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Copperhill Thresholds

Copperhill: days with a maximum temperature at or above 30 C (86 F) in 72 years, most in 1931 with 107.
Copperhill: days with a maximum temperature at or above 90 F (32.2 C) in 72 years, most in 1925 with 76.
Copperhill: nights with a minimum temperature at or below 0 C (32 F) in 72 years, most in 1960 with 125.
Copperhill: days with 10 mm (0.39 in) or more of precipitation in 72 years, most in 1929 with 64.
15 fixed thresholds have at least one qualifying day at Copperhill.

Days at or above 30 C (86 F)

72 years with a qualifying day

Days per year at Copperhill with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 107 in 1931.

Days at or above 30 C (86 F) per year at Copperhill
Year	Days	Decade average
1915	86	69
1916	91	69
1917	39	69
1918	60	69
1920	59	68.7
1922	62	68.7
1923	61	68.7
1924	61	68.7
1925	106	68.7
1926	84	68.7
1927	68	68.7
1928	50	68.7
1929	67	68.7
1930	85	84.4
1931	107	84.4
1932	71	84.4
1933	89	84.4
1934	69	84.4
1935	76	84.4
1936	97	84.4
1937	85	84.4
1938	79	84.4
1939	86	84.4
1940	66	72.3
1941	100	72.3
1942	70	72.3
1943	86	72.3
1944	84	72.3
1945	67	72.3
1946	57	72.3
1947	71	72.3
1948	60	72.3
1949	62	72.3
1950	38	79.8
1951	80	79.8
1952	81	79.8
1953	88	79.8
1954	102	79.8
1955	68	79.8
1956	88	79.8
1957	89	79.8
1958	85	79.8
1959	79	79.8
1960	88	77.7
1961	62	77.7
1962	97	77.7
1963	71	77.7
1964	88	77.7
1965	83	77.7
1966	73	77.7
1967	51	77.7
1968	77	77.7
1969	87	77.7
1970	101	70.9
1971	81	70.9
1972	64	70.9
1973	67	70.9
1974	49	70.9
1975	73	70.9
1976	56	70.9
1977	83	70.9
1978	89	70.9
1979	46	70.9
1980	98	77.4
1981	74	77.4
1982	74	77.4
1983	83	77.4
1984	69	77.4
1985	58	77.4
1986	86	77.4
1991	48	54.5
1995	61	54.5

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

First to last qualifying date each year at Copperhill
Year	First date	Last date
1915	1915-04-24	1915-09-27
1916	1916-04-20	1916-10-07
1917	1917-04-18	1917-09-09
1918	1918-04-25	1918-09-17
1920	1920-05-23	1920-09-27
1922	1922-06-06	1922-10-15
1923	1923-06-03	1923-09-26
1924	1924-05-06	1924-09-14
1925	1925-04-21	1925-10-03
1926	1926-05-01	1926-10-01
1927	1927-04-02	1927-10-24
1928	1928-05-03	1928-10-14
1929	1929-03-24	1929-09-09
1930	1930-04-28	1930-09-26
1931	1931-05-18	1931-10-15
1932	1932-04-24	1932-09-18
1933	1933-05-12	1933-09-28
1934	1934-05-06	1934-09-27
1935	1935-04-26	1935-09-24
1936	1936-03-31	1936-09-29
1937	1937-04-24	1937-09-21
1938	1938-05-03	1938-10-20
1939	1939-05-07	1939-10-10
1940	1940-04-03	1940-09-24
1941	1941-04-20	1941-10-10
1942	1942-04-28	1942-09-20
1943	1943-05-07	1943-09-17
1944	1944-05-16	1944-09-29
1945	1945-05-28	1945-09-27
1946	1946-06-09	1946-09-10
1947	1947-05-16	1947-09-21
1948	1948-05-12	1948-09-23
1949	1949-05-05	1949-09-19
1950	1950-05-05	1950-09-05
1951	1951-05-02	1951-10-07
1952	1952-05-03	1952-10-01
1953	1953-05-02	1953-10-02
1954	1954-05-03	1954-10-06
1955	1955-04-18	1955-09-24
1956	1956-04-29	1956-09-18
1957	1957-04-21	1957-09-23
1958	1958-05-17	1958-09-27
1959	1959-04-10	1959-10-06
1960	1960-04-24	1960-09-22
1961	1961-06-02	1961-09-26
1962	1962-05-01	1962-09-16
1963	1963-04-01	1963-09-29
1964	1964-05-18	1964-09-22
1965	1965-04-23	1965-09-22
1966	1966-05-08	1966-09-11
1967	1967-04-03	1967-10-07
1968	1968-05-16	1968-09-25
1969	1969-05-06	1969-10-13
1970	1970-04-24	1970-10-12
1971	1971-04-19	1971-10-05
1972	1972-04-16	1972-09-23
1973	1973-06-04	1973-09-26
1974	1974-05-05	1974-09-12
1975	1975-05-10	1975-09-10
1976	1976-04-18	1976-09-10
1977	1977-04-13	1977-09-16
1978	1978-05-21	1978-09-24
1979	1979-05-11	1979-09-12
1980	1980-04-24	1980-09-24
1981	1981-04-14	1981-10-01
1982	1982-05-12	1982-10-06
1983	1983-05-02	1983-10-03
1984	1984-04-26	1984-09-25
1985	1985-04-20	1985-09-11
1986	1986-04-26	1986-10-04
1991	1991-05-16	1991-09-19
1995	1995-04-11	1995-09-10

Every Fixed Threshold

Fixed thresholds at Copperhill
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	72	107	1931	61
35 C (95 F): Days	59	30	1930	4
90 F (32.2 C): Days	72	76	1925	32
100 F (37.8 C): Days	13	7	1930	2
0 C (32 F): Ice days (max	68	15	1978	8
0 C (32 F): Frost days (min	72	125	1960	113
-10 C (14 F): Days with min	68	33	1963	18
-20 C (-4 F): Days with min	10	2	1940	2
20 C (68 F): Tropical nights (min	71	74	1916	4
25 C (77 F): Days with min	5	4	1915	1
10 mm (0.39 in): Days with 10 mm or more rain	72	64	1929	53
25 mm (0.98 in): Days with 25 mm or more rain	72	27	1932	19
50 mm (1.97 in): Days with 50 mm or more rain	65	7	1922	4
100 mm (3.94 in): Days with 100 mm or more rain	12	2	1936	2
10 cm (3.9 in): Days with 10 cm or more snowfall	4	1	1968	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1915.

Download the Data

Data for Copperhill 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).

Copperhill Threshold Days by Year (USC00402024)

Key Facts for Copperhill Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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