Blackfoot Dam Weather Records (USC00100920)

Record envelope, standing records and threshold days for Blackfoot Dam (USC00100920), Idaho, United States, with 63 years of record.

Key Facts for Blackfoot Dam

Blackfoot Dam (USC00100920) is a weather station in Idaho, United States at 43.00 latitude and -111.72 longitude, 1,891 m (6,204 ft) above sea level.
The station reports from 1909 to 1971, 63 years of record.
1,464 records set at Blackfoot Dam still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Blackfoot Dam set a daily record low minimum temperature of -7.2 C (19.0 F) on 17 September 1971.

About the Station

Location: Idaho, United States, 43.00 latitude, -111.72 longitude.
Elevation: 1,891 m (6,204 ft).
Period of record: 1909 to 1971, 63 years.
Eligible elements: tmax, tmin, prcp, snow.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Blackfoot Dam. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Blackfoot Dam, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	10.0 C (50.0 F)	-40.0 C (-40.0 F)	n/a	n/a
Feb	11.1 C (52.0 F)	-45.6 C (-50.1 F)	n/a	n/a
Mar	16.7 C (62.1 F)	-33.3 C (-27.9 F)	n/a	n/a
Apr	26.7 C (80.1 F)	-27.2 C (-17.0 F)	n/a	n/a
May	30.0 C (86.0 F)	-13.3 C (8.1 F)	n/a	n/a
Jun	34.4 C (93.9 F)	-8.9 C (16.0 F)	n/a	n/a
Jul	36.1 C (97.0 F)	-4.4 C (24.1 F)	n/a	n/a
Aug	36.7 C (98.1 F)	-6.7 C (19.9 F)	n/a	n/a
Sep	33.3 C (91.9 F)	-12.2 C (10.0 F)	n/a	n/a
Oct	29.4 C (84.9 F)	-21.7 C (-7.1 F)	n/a	n/a
Nov	20.0 C (68.0 F)	-31.7 C (-25.1 F)	n/a	n/a
Dec	15.0 C (59.0 F)	-41.1 C (-42.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Blackfoot Dam still stand. 1917 holds the most, with 75.

Standing records at Blackfoot Dam by the year they were set
Year set	Standing records
1909	36
1910	50
1911	48
1912	32
1913	55
1914	40
1915	36
1916	47
1917	75
1918	53
1919	60
1920	46
1921	23
1932	33
1933	41
1934	54
1935	34
1936	41
1937	34
1938	44
1939	38
1940	39
1941	23
1942	41
1943	33
1944	21
1945	34
1946	34
1947	47
1948	37
1949	4
1950	17
1951	12
1952	7
1953	7
1954	2
1955	13
1956	12
1957	11
1958	14
1959	11
1960	21
1961	7
1962	9
1963	5
1964	10
1965	1
1966	17
1967	8
1968	21
1969	15
1970	8
1971	3

Wettest Day of Each Month

Oct: 44.5 mm (1.8 in)

The wettest day on record for each calendar month at Blackfoot Dam. The most was 44.5 mm (1.8 in) on 6 October 1918.

Record daily precipitation for each month at Blackfoot Dam
Month	Record daily precipitation (mm)	Date
Jan	29.2 mm (1.1 in)	25 January 1911
Feb	40.6 mm (1.6 in)	24 February 1917
Mar	28.4 mm (1.1 in)	15 March 1917
Apr	29.0 mm (1.1 in)	4 April 1942
May	26.7 mm (1.1 in)	21 May 1970
Jun	40.6 mm (1.6 in)	2 June 1955
Jul	29.2 mm (1.1 in)	19 July 1912
Aug	29.5 mm (1.2 in)	1 August 1936
Sep	38.1 mm (1.5 in)	28 September 1919
Oct	44.5 mm (1.8 in)	6 October 1918
Nov	36.3 mm (1.4 in)	21 November 1937
Dec	39.6 mm (1.6 in)	11 December 1916

Period of Record Coverage

1909 to 1971

53 years of record at Blackfoot Dam, 1909 to 1971. 32 years have data for under 90 percent of days and are left out of rankings: 1909, 1914, 1919, 1920, 1921, 1932, 1936, 1939 and others.

Days with data per year at Blackfoot Dam
Year	Days with data	Share of year	Complete
1909	176	48%	No
1910	364	100%	Yes
1911	343	94%	Yes
1912	364	99%	Yes
1913	364	100%	Yes
1914	271	74%	No
1915	335	92%	Yes
1916	366	100%	Yes
1917	360	99%	Yes
1918	363	99%	Yes
1919	288	79%	No
1920	322	88%	No
1921	179	49%	No
1932	178	49%	No
1933	353	97%	Yes
1934	352	96%	Yes
1935	347	95%	Yes
1936	327	89%	No
1937	357	98%	Yes
1938	361	99%	Yes
1939	324	89%	No
1940	354	97%	Yes
1941	360	99%	Yes
1942	358	98%	Yes
1943	350	96%	Yes
1944	362	99%	Yes
1945	365	100%	Yes
1946	358	98%	Yes
1947	362	99%	Yes
1948	306	84%	No
1949	58	16%	No
1950	200	55%	No
1951	121	33%	No
1952	169	46%	No
1953	198	54%	No
1954	54	15%	No
1955	176	48%	No
1956	175	48%	No
1957	189	52%	No
1958	174	48%	No
1959	222	61%	No
1960	197	54%	No
1961	180	49%	No
1962	183	50%	No
1963	195	53%	No
1964	208	57%	No
1965	54	15%	No
1966	209	57%	No
1967	228	62%	No
1968	208	57%	No
1969	201	55%	No
1970	165	45%	No
1971	133	36%	No

Latest Records

Latest records at Blackfoot Dam
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
17 September 1971	Blackfoot Dam, US	daily low min	-7.2 C (19.0 F)	0.5 C (0.9 F)	34 years	17 of 100 (Routine)
16 September 1971	Blackfoot Dam, US	daily low max (Tie)	12.2 C (54.0 F)	tie	37 years	4 of 100 (Routine)
29 August 1971	Blackfoot Dam, US	daily high min	12.8 C (55.0 F)	3.4 C (6.1 F)	57 years	32 of 100 (Routine)
7 August 1971	Blackfoot Dam, US	daily rain	20.8 mm (0.8 in)	9.6 mm (0.38 in)	25 years	20 of 100 (Routine)
8 July 1971	Blackfoot Dam, US	daily rain	4.6 mm (0.18 in)	0.5 mm (0.02 in)	24 years	14 of 100 (Routine)
17 May 1971	Blackfoot Dam, US	daily low max	6.1 C (43.0 F)	1.1 C (2.0 F)	10 years	10 of 100 (Routine)
7 October 1970	Blackfoot Dam, US	daily low min (Tie)	-8.3 C (17.1 F)	tie	33 years	4 of 100 (Routine)
26 September 1970	Blackfoot Dam, US	daily low min	-10.6 C (12.9 F)	1.7 C (3.1 F)	60 years	28 of 100 (Routine)
20 September 1970	Blackfoot Dam, US	daily rain	6.4 mm (0.25 in)	2.3 mm (0.09 in)	11 years	12 of 100 (Routine)
13 September 1970	Blackfoot Dam, US	daily low max	11.1 C (52.0 F)	2.8 C (5.0 F)	3 years	11 of 100 (Routine)
6 September 1970	Blackfoot Dam, US	daily rain	10.9 mm (0.4 in)	6.6 mm (0.26 in)	49 years	20 of 100 (Routine)
6 September 1970	Blackfoot Dam, US	daily low max	10.6 C (51.1 F)	1.1 C (2.0 F)	59 years	25 of 100 (Routine)
5 September 1970	Blackfoot Dam, US	daily rain	19.8 mm (0.8 in)	2.8 mm (0.11 in)	24 years	17 of 100 (Routine)
30 August 1970	Blackfoot Dam, US	daily high min	10.6 C (51.1 F)	0.6 C (1.1 F)	56 years	24 of 100 (Routine)
27 August 1970	Blackfoot Dam, US	daily high min (Tie)	12.2 C (54.0 F)	tie	57 years	5 of 100 (Routine)
26 August 1970	Blackfoot Dam, US	daily high min	12.8 C (55.0 F)	1.1 C (2.0 F)	56 years	25 of 100 (Routine)
14 August 1970	Blackfoot Dam, US	daily high max	33.3 C (91.9 F)	0.5 C (0.9 F)	32 years	16 of 100 (Routine)
28 July 1970	Blackfoot Dam, US	daily rain	13.5 mm (0.5 in)	7.1 mm (0.28 in)	56 years	20 of 100 (Routine)
24 July 1970	Blackfoot Dam, US	daily low min (Tie)	1.7 C (35.1 F)	tie	12 years	2 of 100 (Routine)
23 July 1970	Blackfoot Dam, US	daily low min	0.6 C (33.1 F)	0.5 C (0.9 F)	12 years	10 of 100 (Routine)

Climate Trend

18 complete years, 1910 to 1946

One stripe for each of 18 complete years at Blackfoot Dam, 1910 to 1946. Blue stripes are years cooler than the station's own mean of 3.3 C (37.9 F); red stripes are warmer. The coolest year was 1942, at 2.1 C (35.7 F), and the warmest was 1940, at 4.8 C (40.7 F). The strongest colour marks a difference of 1.6 C (2.9 F).

Annual mean temperature at Blackfoot Dam as warming stripes, 1910 to 1946
Year	Annual mean temperature	Difference from the station mean
1910	4.5 C	+1.23 C
1911	3.6 C	+0.27 C
1912	2.4 C	-0.86 C
1913	3.7 C	+0.42 C
1916	2.6 C	-0.67 C
1917	2.3 C	-0.94 C
1918	3.8 C	+0.54 C
1933	2.8 C	-0.50 C
1936	3.0 C	-0.28 C
1937	3.0 C	-0.25 C
1938	3.5 C	+0.20 C
1940	4.8 C	+1.55 C
1941	3.5 C	+0.17 C
1942	2.1 C	-1.20 C
1943	3.3 C	-0.03 C
1944	2.7 C	-0.58 C
1945	3.2 C	-0.11 C
1946	4.3 C	+1.05 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1909 to 1971

Yearly extremes at Blackfoot Dam: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	36.7 C (98.1 F)	1913	33.3 C (91.9 F)	53
Coldest night (TNn)	-45.6 C (-50.1 F)	1942	-27.8 C (-18.0 F)	53
Wettest day (Rx1day)	44.5 mm (1.8 in)	1918	20.8 mm (0.8 in)	53
Wettest five days (Rx5day)	82.8 mm (3.3 in)	1919	43.2 mm (1.7 in)	53
Longest dry spell (CDD)	65 days	1911	29 days	53

Hottest day (TXx)

The hottest day of the year at Blackfoot Dam, 1909 to 1971. The record is 36.7 C (98.1 F) in 1913, marked on the chart; the median year is 33.3 C (91.9 F).

Hottest day (TXx) at Blackfoot Dam by year
Year	Hottest day (TXx)
1909	32.8 C (91.0 F)
1910	32.2 C (90.0 F)
1911	32.8 C (91.0 F)
1912	30.6 C (87.1 F)
1913	36.7 C (98.1 F)
1914	30.6 C (87.1 F)
1915	32.2 C (90.0 F)
1916	31.7 C (89.1 F)
1917	32.8 C (91.0 F)
1918	33.9 C (93.0 F)
1919	35.6 C (96.1 F)
1920	36.7 C (98.1 F)
1921	31.7 C (89.1 F)
1932	31.7 C (89.1 F)
1933	34.4 C (93.9 F)
1934	36.1 C (97.0 F)
1935	33.9 C (93.0 F)
1936	33.9 C (93.0 F)
1937	32.8 C (91.0 F)
1938	31.7 C (89.1 F)
1939	35.0 C (95.0 F)
1940	35.6 C (96.1 F)
1941	32.8 C (91.0 F)
1942	33.3 C (91.9 F)
1943	33.3 C (91.9 F)
1944	31.7 C (89.1 F)
1945	33.9 C (93.0 F)
1946	34.4 C (93.9 F)
1947	32.8 C (91.0 F)
1948	33.3 C (91.9 F)
1949	33.3 C (91.9 F)
1950	33.3 C (91.9 F)
1951	35.6 C (96.1 F)
1952	31.1 C (88.0 F)
1953	33.3 C (91.9 F)
1954	31.1 C (88.0 F)
1955	32.2 C (90.0 F)
1956	33.3 C (91.9 F)
1957	31.1 C (88.0 F)
1958	33.3 C (91.9 F)
1959	33.3 C (91.9 F)
1960	35.0 C (95.0 F)
1961	33.9 C (93.0 F)
1962	33.3 C (91.9 F)
1963	32.2 C (90.0 F)
1964	31.7 C (89.1 F)
1965	23.9 C (75.0 F)
1966	33.9 C (93.0 F)
1967	31.1 C (88.0 F)
1968	31.7 C (89.1 F)
1969	34.4 C (93.9 F)
1970	33.3 C (91.9 F)
1971	32.8 C (91.0 F)

Coldest night (TNn)

The coldest night of the year at Blackfoot Dam, 1909 to 1971. The record is -45.6 C (-50.1 F) in 1942, marked on the chart; the median year is -27.8 C (-18.0 F).

Coldest night (TNn) at Blackfoot Dam by year
Year	Coldest night (TNn)
1909	-30.6 C (-23.1 F)
1910	-34.4 C (-29.9 F)
1911	-35.0 C (-31.0 F)
1912	-39.4 C (-38.9 F)
1913	-34.4 C (-29.9 F)
1914	-36.7 C (-34.1 F)
1915	-36.1 C (-33.0 F)
1916	-35.6 C (-32.1 F)
1917	-37.2 C (-35.0 F)
1918	-38.9 C (-38.0 F)
1919	-41.1 C (-42.0 F)
1920	-33.3 C (-27.9 F)
1921	-10.0 C (14.0 F)
1932	-35.0 C (-31.0 F)
1933	-40.6 C (-41.1 F)
1934	-24.4 C (-11.9 F)
1935	-34.4 C (-29.9 F)
1936	-35.6 C (-32.1 F)
1937	-40.0 C (-40.0 F)
1938	-28.9 C (-20.0 F)
1939	-30.0 C (-22.0 F)
1940	-28.9 C (-20.0 F)
1941	-34.4 C (-29.9 F)
1942	-45.6 C (-50.1 F)
1943	-35.0 C (-31.0 F)
1944	-31.1 C (-24.0 F)
1945	-36.1 C (-33.0 F)
1946	-27.8 C (-18.0 F)
1947	-24.4 C (-11.9 F)
1948	-35.0 C (-31.0 F)
1949	-6.1 C (21.0 F)
1950	-19.4 C (-2.9 F)
1951	-6.7 C (19.9 F)
1952	-5.6 C (21.9 F)
1953	-18.9 C (-2.0 F)
1954	-16.7 C (1.9 F)
1955	-14.4 C (6.1 F)
1956	-14.4 C (6.1 F)
1957	-13.3 C (8.1 F)
1958	-13.3 C (8.1 F)
1959	-27.8 C (-18.0 F)
1960	-19.4 C (-2.9 F)
1961	-9.4 C (15.1 F)
1962	-19.4 C (-2.9 F)
1963	-16.7 C (1.9 F)
1964	-20.6 C (-5.1 F)
1965	-10.0 C (14.0 F)
1966	-15.6 C (3.9 F)
1967	-16.1 C (3.0 F)
1968	-14.4 C (6.1 F)
1969	-17.2 C (1.0 F)
1970	-11.1 C (12.0 F)
1971	-8.3 C (17.1 F)

Wettest day (Rx1day)

The wettest day of the year at Blackfoot Dam, 1909 to 1971. The record is 44.5 mm (1.8 in) in 1918, marked on the chart; the median year is 20.8 mm (0.8 in).

Wettest day (Rx1day) at Blackfoot Dam by year
Year	Wettest day (Rx1day)
1909	20.1 mm (0.8 in)
1910	18.0 mm (0.7 in)
1911	33.0 mm (1.3 in)
1912	29.2 mm (1.1 in)
1913	19.1 mm (0.8 in)
1914	36.1 mm (1.4 in)
1915	20.6 mm (0.8 in)
1916	39.6 mm (1.6 in)
1917	40.6 mm (1.6 in)
1918	44.5 mm (1.8 in)
1919	38.1 mm (1.5 in)
1920	22.6 mm (0.9 in)
1921	16.5 mm (0.6 in)
1932	18.8 mm (0.7 in)
1933	16.8 mm (0.7 in)
1934	32.0 mm (1.3 in)
1935	25.9 mm (1.0 in)
1936	37.1 mm (1.5 in)
1937	36.3 mm (1.4 in)
1938	17.0 mm (0.7 in)
1939	19.6 mm (0.8 in)
1940	29.5 mm (1.2 in)
1941	20.8 mm (0.8 in)
1942	29.0 mm (1.1 in)
1943	20.3 mm (0.8 in)
1944	22.4 mm (0.9 in)
1945	27.7 mm (1.1 in)
1946	29.0 mm (1.1 in)
1947	24.4 mm (1.0 in)
1948	30.0 mm (1.2 in)
1949	17.0 mm (0.7 in)
1950	18.5 mm (0.7 in)
1951	17.0 mm (0.7 in)
1952	17.3 mm (0.7 in)
1953	24.4 mm (1.0 in)
1954	4.1 mm (0.16 in)
1955	40.6 mm (1.6 in)
1956	12.7 mm (0.5 in)
1957	19.1 mm (0.8 in)
1958	9.4 mm (0.37 in)
1959	18.0 mm (0.7 in)
1960	9.9 mm (0.39 in)
1961	31.0 mm (1.2 in)
1962	17.0 mm (0.7 in)
1963	19.8 mm (0.8 in)
1964	30.5 mm (1.2 in)
1965	12.4 mm (0.5 in)
1966	25.9 mm (1.0 in)
1967	37.1 mm (1.5 in)
1968	20.3 mm (0.8 in)
1969	16.0 mm (0.6 in)
1970	26.7 mm (1.1 in)
1971	20.8 mm (0.8 in)

Wettest five days (Rx5day)

The wettest five days of the year at Blackfoot Dam, 1909 to 1971. The record is 82.8 mm (3.3 in) in 1919, marked on the chart; the median year is 43.2 mm (1.7 in).

Wettest five days (Rx5day) at Blackfoot Dam by year
Year	Wettest five days (Rx5day)
1909	60.0 mm (2.4 in)
1910	31.7 mm (1.2 in)
1911	55.8 mm (2.2 in)
1912	47.5 mm (1.9 in)
1913	50.1 mm (2.0 in)
1914	61.5 mm (2.4 in)
1915	52.2 mm (2.1 in)
1916	43.2 mm (1.7 in)
1917	54.1 mm (2.1 in)
1918	49.8 mm (2.0 in)
1919	82.8 mm (3.3 in)
1920	54.4 mm (2.1 in)
1921	39.4 mm (1.6 in)
1932	19.6 mm (0.8 in)
1933	33.8 mm (1.3 in)
1934	53.6 mm (2.1 in)
1935	29.2 mm (1.1 in)
1936	55.5 mm (2.2 in)
1937	47.2 mm (1.9 in)
1938	39.6 mm (1.6 in)
1939	35.5 mm (1.4 in)
1940	36.4 mm (1.4 in)
1941	55.1 mm (2.2 in)
1942	31.3 mm (1.2 in)
1943	59.6 mm (2.3 in)
1944	48.5 mm (1.9 in)
1945	66.2 mm (2.6 in)
1946	39.2 mm (1.5 in)
1947	50.4 mm (2.0 in)
1948	76.3 mm (3.0 in)
1949	18.0 mm (0.7 in)
1950	26.6 mm (1.0 in)
1951	24.6 mm (1.0 in)
1952	41.5 mm (1.6 in)
1953	44.5 mm (1.8 in)
1954	4.1 mm (0.16 in)
1955	69.8 mm (2.7 in)
1956	23.4 mm (0.9 in)
1957	45.5 mm (1.8 in)
1958	18.8 mm (0.7 in)
1959	30.2 mm (1.2 in)
1960	28.5 mm (1.1 in)
1961	55.6 mm (2.2 in)
1962	31.5 mm (1.2 in)
1963	34.6 mm (1.4 in)
1964	57.9 mm (2.3 in)
1965	22.6 mm (0.9 in)
1966	33.5 mm (1.3 in)
1967	59.0 mm (2.3 in)
1968	53.9 mm (2.1 in)
1969	28.2 mm (1.1 in)
1970	31.5 mm (1.2 in)
1971	33.5 mm (1.3 in)

Longest dry spell (CDD)

The longest dry spell of the year at Blackfoot Dam, 1909 to 1971. The record is 65 days in 1911, marked on the chart; the median year is 29 days.

Longest dry spell (CDD) at Blackfoot Dam by year
Year	Longest dry spell (CDD)
1909	23 days
1910	34 days
1911	65 days
1912	15 days
1913	24 days
1914	25 days
1915	37 days
1916	37 days
1917	39 days
1918	23 days
1919	53 days
1920	18 days
1921	28 days
1932	24 days
1933	36 days
1934	24 days
1935	59 days
1936	35 days
1937	26 days
1938	30 days
1939	58 days
1940	46 days
1941	13 days
1942	28 days
1943	39 days
1944	58 days
1945	19 days
1946	30 days
1947	27 days
1948	38 days
1949	26 days
1950	25 days
1951	33 days
1952	32 days
1953	37 days
1954	22 days
1955	19 days
1956	39 days
1957	14 days
1958	49 days
1959	29 days
1960	34 days
1961	23 days
1962	34 days
1963	43 days
1964	39 days
1965	43 days
1966	26 days
1967	21 days
1968	24 days
1969	21 days
1970	29 days
1971	26 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Download the Data

Data for Blackfoot Dam standing records by year: CSV or JSON. Field meanings are on the data page.
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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).