Isachsen Threshold Days by Year (CA002402600)

8 fixed thresholds counted per year at Isachsen (CA002402600): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Isachsen Thresholds

Isachsen: nights with a minimum temperature at or below 0 C (32 F) in 29 years, most in 1961 with 358.
Isachsen: nights with a minimum temperature at or below -10 C (14 F) in 29 years, most in 1956 with 272.
Isachsen: nights with a minimum temperature at or below -20 C (-4 F) in 29 years, most in 1972 with 229.
Isachsen: nights with a minimum temperature at or below -30 C (-22 F) in 29 years, most in 1974 with 176.
8 fixed thresholds have at least one qualifying day at Isachsen.

Nights at or below 0 C (32 F)

29 years with a qualifying day

Days per year at Isachsen with nights with a minimum temperature at or below 0 C (32 F), with the decade average as a line. The most was 358 in 1961.

Nights at or below 0 C (32 F) per year at Isachsen
Year	Days	Decade average
1949	331	331
1950	346	332.9
1951	327	332.9
1952	333	332.9
1953	353	332.9
1954	332	332.9
1955	336	332.9
1956	346	332.9
1957	325	332.9
1958	303	332.9
1959	328	332.9
1960	330	343.7
1961	358	343.7
1962	330	343.7
1963	336	343.7
1964	355	343.7
1965	354	343.7
1966	330	343.7
1967	349	343.7
1968	344	343.7
1969	351	343.7
1970	351	342.6
1971	327	342.6
1972	354	342.6
1973	333	342.6
1974	348	342.6
1975	348	342.6
1976	348	342.6
1977	332	342.6

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

First to last qualifying date each year at Isachsen
Year	First date	Last date
1949	1949-01-01	1949-12-31
1950	1950-01-01	1950-12-31
1951	1951-01-01	1951-12-31
1952	1952-01-01	1952-12-31
1953	1953-01-01	1953-12-31
1954	1954-01-01	1954-12-31
1955	1955-01-01	1955-12-31
1956	1956-01-01	1956-12-31
1957	1957-01-01	1957-12-31
1958	1958-01-01	1958-12-31
1959	1959-01-01	1959-12-31
1960	1960-01-01	1960-12-31
1961	1961-01-01	1961-12-31
1962	1962-01-01	1962-12-31
1963	1963-01-01	1963-12-31
1964	1964-01-01	1964-12-31
1965	1965-01-01	1965-12-31
1966	1966-01-01	1966-12-31
1967	1967-01-01	1967-12-31
1968	1968-01-01	1968-12-31
1969	1969-01-01	1969-12-31
1970	1970-01-01	1970-12-31
1971	1971-01-01	1971-12-31
1972	1972-01-01	1972-12-31
1973	1973-01-01	1973-12-31
1974	1974-01-01	1974-12-31
1975	1975-01-01	1975-12-31
1976	1976-01-01	1976-12-31
1977	1977-01-01	1977-12-31

Every Fixed Threshold

Fixed thresholds at Isachsen
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
0 C (32 F): Ice days (max	28	301	1972	282
0 C (32 F): Frost days (min	29	358	1961	332
-10 C (14 F): Days with min	29	272	1956	257
-20 C (-4 F): Days with min	29	229	1972	204
-30 C (-22 F): Days with min	29	176	1974	151
-40 C (-40 F): Days with min	29	77	1974	68
10 mm (0.39 in): Days with 10 mm or more rain	12	3	1951	1
10 cm (3.9 in): Days with 10 cm or more snowfall	4	1	1959	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1950.

Download the Data

Data for Isachsen 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).

Isachsen Threshold Days by Year (CA002402600)

Key Facts for Isachsen Thresholds

Nights at or below 0 C (32 F)

Every Fixed Threshold

Download the Data

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