Grand Canyon HQ Threshold Days by Year (USC00023591)

13 fixed thresholds counted per year at Grand Canyon HQ (USC00023591): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Grand Canyon HQ Thresholds

Grand Canyon HQ: days with 10 mm (0.39 in) or more of precipitation in 47 years, most in 1940 with 21.
Grand Canyon HQ: days with 10 cm (3.9 in) or more of snowfall in 47 years, most in 1932 with 10.
Grand Canyon HQ: days with a maximum temperature at or above 30 C (86 F) in 43 years, most in 1924 with 83.
Grand Canyon HQ: days with a maximum temperature at or below 0 C (32 F) in 43 years, most in 1949 with 43.
13 fixed thresholds have at least one qualifying day at Grand Canyon HQ.

Days at or above 30 C (86 F)

43 years with a qualifying day

Days per year at Grand Canyon HQ with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 83 in 1924.

Days at or above 30 C (86 F) per year at Grand Canyon HQ
Year	Days	Decade average
1913	23	20.9
1914	12	20.9
1915	9	20.9
1916	3	20.9
1917	33	20.9
1918	24	20.9
1919	42	20.9
1921	14	36.9
1922	40	36.9
1923	22	36.9
1924	83	36.9
1925	32	36.9
1926	33	36.9
1927	35	36.9
1928	42	36.9
1929	31	36.9
1930	25	40.7
1931	44	40.7
1932	63	40.7
1933	63	40.7
1934	34	40.7
1935	43	40.7
1936	39	40.7
1937	30	40.7
1938	20	40.7
1939	46	40.7
1940	48	32.5
1941	26	32.5
1942	43	32.5
1943	22	32.5
1944	38	32.5
1945	35	32.5
1946	19	32.5
1947	29	32.5
1948	31	32.5
1949	34	32.5
1950	32	33
1951	41	33
1952	25	33
1953	39	33
1954	23	33
1955	29	33
1956	42	33

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

First to last qualifying date each year at Grand Canyon HQ
Year	First date	Last date
1913	1913-06-23	1913-08-24
1914	1914-06-17	1914-08-17
1915	1915-06-22	1915-08-29
1916	1916-06-15	1916-07-11
1917	1917-06-15	1917-08-25
1918	1918-06-06	1918-08-26
1919	1919-06-16	1919-09-16
1921	1921-06-26	1921-08-03
1922	1922-06-08	1922-09-14
1923	1923-06-11	1923-08-28
1924	1924-06-03	1924-09-07
1925	1925-05-03	1925-08-21
1926	1926-06-11	1926-08-27
1927	1927-06-05	1927-08-23
1928	1928-06-06	1928-09-18
1929	1929-06-14	1929-08-19
1930	1930-06-06	1930-09-04
1931	1931-06-14	1931-08-28
1932	1932-06-12	1932-09-17
1933	1933-05-28	1933-09-06
1934	1934-06-29	1934-09-04
1935	1935-06-11	1935-09-17
1936	1936-06-10	1936-08-28
1937	1937-05-15	1937-09-18
1938	1938-06-03	1938-08-22
1939	1939-06-09	1939-09-01
1940	1940-06-12	1940-08-16
1941	1941-06-17	1941-08-20
1942	1942-05-24	1942-08-18
1943	1943-06-17	1943-08-27
1944	1944-06-28	1944-09-22
1945	1945-06-13	1945-09-12
1946	1946-06-03	1946-08-03
1947	1947-06-15	1947-09-06
1948	1948-06-29	1948-09-13
1949	1949-06-15	1949-09-22
1950	1950-06-20	1950-09-05
1951	1951-05-26	1951-08-27
1952	1952-06-17	1952-09-06
1953	1953-06-13	1953-08-20
1954	1954-06-18	1954-08-31
1955	1955-06-07	1955-09-12
1956	1956-05-31	1956-09-19

Every Fixed Threshold

Fixed thresholds at Grand Canyon HQ
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	43	83	1924	42
35 C (95 F): Days	18	8	1933	1
90 F (32.2 C): Days	41	51	1924	10
0 C (32 F): Ice days (max	43	43	1949	8
0 C (32 F): Frost days (min	43	209	1913	157
-10 C (14 F): Days with min	43	74	1913	19
-20 C (-4 F): Days with min	22	9	1949	5
20 C (68 F): Tropical nights (min	3	1	1928	1
10 mm (0.39 in): Days with 10 mm or more rain	47	21	1940	3
25 mm (0.98 in): Days with 25 mm or more rain	40	4	1927	1
50 mm (1.97 in): Days with 50 mm or more rain	6	1	1916	1
10 cm (3.9 in): Days with 10 cm or more snowfall	47	10	1932	4
25 cm (9.8 in): Days with 25 cm or more snowfall	23	2	1919	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1913.

Download the Data

Data for Grand Canyon HQ 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).

Grand Canyon HQ Threshold Days by Year (USC00023591)

Key Facts for Grand Canyon HQ Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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