Kennecott Threshold Days by Year (USC00504555)

11 fixed thresholds counted per year at Kennecott (USC00504555): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Kennecott Thresholds

Kennecott: nights with a minimum temperature at or below 0 C (32 F) in 24 years, most in 1940 with 252.
Kennecott: nights with a minimum temperature at or below -10 C (14 F) in 24 years, most in 1917 with 141.
Kennecott: nights with a minimum temperature at or below -20 C (-4 F) in 24 years, most in 1933 with 80.
Kennecott: days with a maximum temperature at or below 0 C (32 F) in 23 years, most in 1939 with 138.
11 fixed thresholds have at least one qualifying day at Kennecott.

Nights at or below 0 C (32 F)

24 years with a qualifying day

Days per year at Kennecott with nights with a minimum temperature at or below 0 C (32 F), with the decade average as a line. The most was 252 in 1940.

Nights at or below 0 C (32 F) per year at Kennecott
Year	Days	Decade average
1917	230	220
1918	210	220
1921	218	223.2
1926	208	223.2
1927	235	223.2
1928	236	223.2
1929	219	223.2
1930	241	229.1
1931	237	229.1
1932	228	229.1
1933	242	229.1
1934	211	229.1
1935	228	229.1
1936	221	229.1
1937	226	229.1
1938	208	229.1
1939	249	229.1
1940	252	239.4
1941	252	239.4
1942	230	239.4
1943	227	239.4
1944	249	239.4
1945	243	239.4
1946	223	239.4

For each year, a bar from the first to the last day at Kennecott meeting 0 C (32 F).

First to last qualifying date each year at Kennecott
Year	First date	Last date
1917	1917-01-01	1917-12-31
1918	1918-01-01	1918-12-31
1921	1921-01-01	1921-12-30
1926	1926-01-01	1926-12-31
1927	1927-01-01	1927-12-31
1928	1928-01-01	1928-12-31
1929	1929-01-01	1929-12-31
1930	1930-01-01	1930-12-31
1931	1931-01-01	1931-12-31
1932	1932-01-01	1932-12-31
1933	1933-01-01	1933-12-31
1934	1934-01-01	1934-12-31
1935	1935-01-01	1935-12-31
1936	1936-01-01	1936-12-30
1937	1937-01-01	1937-12-31
1938	1938-01-01	1938-12-31
1939	1939-01-01	1939-12-31
1940	1940-01-01	1940-12-31
1941	1941-01-01	1941-12-30
1942	1942-01-01	1942-12-31
1943	1943-01-01	1943-12-31
1944	1944-01-01	1944-12-31
1945	1945-01-01	1945-12-31
1946	1946-01-01	1946-12-31

Every Fixed Threshold

Fixed thresholds at Kennecott
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
0 C (32 F): Ice days (max	23	138	1939	112
0 C (32 F): Frost days (min	24	252	1940	223
-10 C (14 F): Days with min	24	141	1917	132
-20 C (-4 F): Days with min	24	80	1933	49
-30 C (-22 F): Days with min	23	31	1917	13
-40 C (-40 F): Days with min	3	2	1917	1
10 mm (0.39 in): Days with 10 mm or more rain	22	24	1944	17
25 mm (0.98 in): Days with 25 mm or more rain	20	7	1934	3
50 mm (1.97 in): Days with 50 mm or more rain	4	2	1932	1
10 cm (3.9 in): Days with 10 cm or more snowfall	6	11	1937	6
25 cm (9.8 in): Days with 25 cm or more snowfall	5	1	1927	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1917.

Download the Data

Data for Kennecott 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).

Kennecott Threshold Days by Year (USC00504555)

Key Facts for Kennecott Thresholds

Nights at or below 0 C (32 F)

Every Fixed Threshold

Download the Data

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