Blackfoot Dam Threshold Days by Year (USC00100920)

13 fixed thresholds counted per year at Blackfoot Dam (USC00100920): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Blackfoot Dam Thresholds

Blackfoot Dam: nights with a minimum temperature at or below 0 C (32 F) in 23 years, most in 1916 with 269.
Blackfoot Dam: nights with a minimum temperature at or below -10 C (14 F) in 23 years, most in 1933 with 119.
Blackfoot Dam: nights with a minimum temperature at or below -20 C (-4 F) in 23 years, most in 1942 with 50.
Blackfoot Dam: days with a maximum temperature at or above 30 C (86 F) in 21 years, most in 1940 with 35.
13 fixed thresholds have at least one qualifying day at Blackfoot Dam.

Days at or above 30 C (86 F)

21 years with a qualifying day

Days per year at Blackfoot Dam with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 35 in 1940.

Days at or above 30 C (86 F) per year at Blackfoot Dam
Year	Days	Decade average
1910	17	11.8
1911	13	11.8
1912	1	11.8
1913	9	11.8
1915	15	11.8
1916	12	11.8
1917	12	11.8
1918	15	11.8
1933	26	20.2
1934	24	20.2
1935	23	20.2
1937	20	20.2
1938	8	20.2
1940	35	20.6
1941	10	20.6
1942	35	20.6
1943	17	20.6
1944	9	20.6
1945	14	20.6
1946	25	20.6
1947	20	20.6

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

First to last qualifying date each year at Blackfoot Dam
Year	First date	Last date
1910	1910-06-26	1910-08-19
1911	1911-06-12	1911-08-20
1912	1912-06-27	1912-06-27
1913	1913-08-16	1913-08-28
1915	1915-07-20	1915-08-31
1916	1916-06-17	1916-09-01
1917	1917-07-09	1917-07-26
1918	1918-06-10	1918-09-04
1933	1933-07-04	1933-08-18
1934	1934-07-03	1934-08-29
1935	1935-07-13	1935-08-22
1937	1937-06-22	1937-09-01
1938	1938-07-24	1938-08-25
1940	1940-06-16	1940-08-30
1941	1941-07-16	1941-08-08
1942	1942-07-04	1942-09-03
1943	1943-07-19	1943-09-11
1944	1944-07-17	1944-09-09
1945	1945-07-21	1945-08-29
1946	1946-07-12	1946-09-30
1947	1947-07-13	1947-09-06

Every Fixed Threshold

Fixed thresholds at Blackfoot Dam
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	21	35	1940	20
35 C (95 F): Days	3	3	1934	1
90 F (32.2 C): Days	17	15	1940	6
0 C (32 F): Ice days (max	21	94	1917	56
0 C (32 F): Frost days (min	23	269	1916	240
-10 C (14 F): Days with min	23	119	1933	84
-20 C (-4 F): Days with min	23	50	1942	28
-30 C (-22 F): Days with min	19	11	1917	2
-40 C (-40 F): Days with min	4	2	1933	2
10 mm (0.39 in): Days with 10 mm or more rain	20	15	1912	8
25 mm (0.98 in): Days with 25 mm or more rain	12	2	1911	1
10 cm (3.9 in): Days with 10 cm or more snowfall	13	8	1916	1
25 cm (9.8 in): Days with 25 cm or more snowfall	3	2	1916	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1910.

Download the Data

Data for Blackfoot Dam 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).

Blackfoot Dam Threshold Days by Year (USC00100920)

Key Facts for Blackfoot Dam Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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