Record envelope, standing records and threshold days for Anderson Dam (USC00100282), Idaho, United States, with 65 years of record.
Key Facts for Anderson Dam
Anderson Dam (USC00100282) is a weather station in Idaho, United States at 43.36 latitude and -115.45 longitude, 1,183 m (3,882 ft) above sea level.
The station reports from 1942 to 2006, 65 years of record.
1,464 records set at Anderson Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Anderson Dam tied a daily record high minimum temperature of 17.2 C (63.0 F) on 28 June 2006.
About the Station
Location: Idaho, United States, 43.36 latitude, -115.45 longitude.
Elevation: 1,183 m (3,882 ft).
Period of record: 1942 to 2006, 65 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Anderson 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 Anderson Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
12.8 C (55.0 F)
-29.4 C (-20.9 F)
n/a
n/a
Feb
17.8 C (64.0 F)
-28.9 C (-20.0 F)
n/a
n/a
Mar
23.9 C (75.0 F)
-24.4 C (-11.9 F)
n/a
n/a
Apr
31.1 C (88.0 F)
-11.7 C (10.9 F)
n/a
n/a
May
36.7 C (98.1 F)
-5.6 C (21.9 F)
n/a
n/a
Jun
40.0 C (104.0 F)
-1.1 C (30.0 F)
n/a
n/a
Jul
43.9 C (111.0 F)
2.2 C (36.0 F)
n/a
n/a
Aug
41.1 C (106.0 F)
2.8 C (37.0 F)
n/a
n/a
Sep
42.2 C (108.0 F)
-2.8 C (27.0 F)
n/a
n/a
Oct
33.3 C (91.9 F)
-10.6 C (12.9 F)
n/a
n/a
Nov
24.4 C (75.9 F)
-18.9 C (-2.0 F)
n/a
n/a
Dec
15.6 C (60.1 F)
-28.3 C (-18.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Anderson Dam still stand. 1949 holds the most, with 64.
Standing records at Anderson Dam by the year they were set
Year set
Standing records
1942
51
1943
42
1944
18
1945
42
1946
24
1947
28
1948
31
1949
64
1950
34
1951
23
1952
24
1953
29
1954
34
1955
33
1956
28
1957
15
1958
25
1959
18
1960
22
1961
31
1962
33
1963
37
1964
32
1965
25
1966
24
1967
33
1968
20
1969
25
1970
20
1971
17
1972
33
1973
11
1974
22
1975
27
1976
20
1977
39
1978
22
1979
10
1980
14
1981
14
1982
16
1983
21
1984
13
1985
27
1986
15
1987
17
1988
15
1989
16
1990
21
1991
6
1992
28
1993
19
1994
12
1995
20
1996
27
1997
17
1998
13
1999
18
2000
15
2002
7
2003
12
2004
4
2005
10
2006
1
All-Time Record Progression
3 new records
3 all-time records were set at Anderson Dam between 5 February 1989 and 9 December 2004. Each dot is a new record.
When Anderson Dam set new all-time records
Date
Kind
Detail
1989-02-05
Record low maximum temperature
Record low maximum temperature -18.9 C (-2.0 F)
2000-07-13
Record high maximum temperature
Record high maximum temperature 43.9 C (111.0 F)
2004-12-09
Record daily precipitation
Record daily precipitation 58.7 mm (2.3 in)
Wettest Day of Each Month
Dec: 58.7 mm (2.3 in)
The wettest day on record for each calendar month at Anderson Dam. The most was 58.7 mm (2.3 in) on 9 December 2004.
Record daily precipitation for each month at Anderson Dam
Month
Record daily precipitation (mm)
Date
Jan
52.6 mm (2.1 in)
27 January 1970
Feb
51.6 mm (2.0 in)
8 February 1960
Mar
39.9 mm (1.6 in)
30 March 1959
Apr
35.1 mm (1.4 in)
28 April 1951
May
32.8 mm (1.3 in)
10 May 2005
Jun
30.5 mm (1.2 in)
29 June 1970
Jul
29.2 mm (1.1 in)
10 July 1983
Aug
42.9 mm (1.7 in)
21 August 1965
Sep
40.6 mm (1.6 in)
8 September 1950
Oct
46.5 mm (1.8 in)
23 October 1985
Nov
43.9 mm (1.7 in)
13 November 1984
Dec
58.7 mm (2.3 in)
9 December 2004
Period of Record Coverage
1942 to 2006
Complete yearUnder 90 percent of days
64 years of record at Anderson Dam, 1942 to 2006. 26 years have data for under 90 percent of days and are left out of rankings: 1953, 1981, 1982, 1983, 1984, 1985, 1986, 1987 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 32 complete years at Anderson Dam, 1942 to 1978. Blue stripes are years cooler than the station's own mean of 9.4 C (49.0 F); red stripes are warmer. The coolest year was 1964, at 8.4 C (47.0 F), and the warmest was 1958, at 10.4 C (50.7 F). The strongest colour marks a difference of 1.1 C (2.0 F).
Annual mean temperature at Anderson Dam as warming stripes, 1942 to 1978
Year
Annual mean temperature
Difference from the station mean
1942
8.5 C
-0.92 C
1944
9.3 C
-0.16 C
1945
8.7 C
-0.70 C
1946
8.9 C
-0.49 C
1947
9.8 C
+0.38 C
1948
8.6 C
-0.83 C
1949
8.8 C
-0.67 C
1950
8.8 C
-0.62 C
1951
8.9 C
-0.56 C
1952
8.9 C
-0.51 C
1954
10.3 C
+0.85 C
1955
8.5 C
-0.88 C
1958
10.4 C
+0.97 C
1959
9.9 C
+0.50 C
1960
9.7 C
+0.24 C
1961
10.1 C
+0.68 C
1962
9.4 C
+0.01 C
1963
10.3 C
+0.84 C
1964
8.4 C
-1.06 C
1965
9.6 C
+0.20 C
1966
10.3 C
+0.90 C
1967
10.4 C
+0.93 C
1969
9.7 C
+0.24 C
1970
9.4 C
-0.04 C
1971
9.0 C
-0.44 C
1972
9.5 C
+0.07 C
1973
9.9 C
+0.51 C
1974
9.5 C
+0.10 C
1975
8.9 C
-0.54 C
1976
9.6 C
+0.18 C
1977
10.2 C
+0.82 C
1978
9.5 C
+0.07 C
The annual mean temperature here has risen by 0.24 C (0.04 to 0.43) per decade over 1942 to 1978. In Fahrenheit: 0.4 F (0.1 to 0.8) per decade. The slope is a straight line fitted to 32 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Anderson Dam
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.24 C (0.04 to 0.43) per decade
0.4 F (0.1 to 0.8) per decade
1942 to 1978
32
Rise
Mean daily maximum
0.1 C (-0.2 to 0.3) per decade
0.1 F (-0.3 to 0.5) per decade
1942 to 1978
32
Not clearly different from zero
Mean daily minimum
0.4 C (0.2 to 0.7) per decade
0.8 F (0.3 to 1.2) per decade
1942 to 1978
32
Rise
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
1942 to 2006
Yearly extremes at Anderson Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
43.9 C (111.0 F)
2000
38.9 C (102.0 F)
64
Coldest night (TNn)
-29.4 C (-20.9 F)
1949
-20.3 C (-4.5 F)
64
Wettest day (Rx1day)
58.7 mm (2.3 in)
2004
35.7 mm (1.4 in)
64
Wettest five days (Rx5day)
150.1 mm (5.9 in)
1964
58.5 mm (2.3 in)
64
Longest dry spell (CDD)
100 days
1944
45 days
64
Hottest day (TXx)
The hottest day of the year at Anderson Dam, 1942 to 2006. The record is 43.9 C (111.0 F) in 2000, marked on the chart; the median year is 38.9 C (102.0 F).
Hottest day (TXx) at Anderson Dam by year
Year
Hottest day (TXx)
1942
40.0 C (104.0 F)
1943
41.1 C (106.0 F)
1944
37.2 C (99.0 F)
1945
38.3 C (100.9 F)
1946
41.1 C (106.0 F)
1947
39.4 C (102.9 F)
1948
38.9 C (102.0 F)
1949
41.1 C (106.0 F)
1950
42.2 C (108.0 F)
1951
38.9 C (102.0 F)
1952
37.2 C (99.0 F)
1953
39.4 C (102.9 F)
1954
40.6 C (105.1 F)
1955
38.9 C (102.0 F)
1956
40.6 C (105.1 F)
1957
37.2 C (99.0 F)
1958
38.3 C (100.9 F)
1959
40.6 C (105.1 F)
1960
41.7 C (107.1 F)
1961
40.6 C (105.1 F)
1962
38.3 C (100.9 F)
1963
37.8 C (100.0 F)
1964
37.8 C (100.0 F)
1965
37.2 C (99.0 F)
1966
39.4 C (102.9 F)
1967
40.0 C (104.0 F)
1968
39.4 C (102.9 F)
1969
40.6 C (105.1 F)
1970
38.3 C (100.9 F)
1971
38.9 C (102.0 F)
1972
38.9 C (102.0 F)
1973
41.1 C (106.0 F)
1974
38.9 C (102.0 F)
1975
40.0 C (104.0 F)
1976
38.3 C (100.9 F)
1977
38.3 C (100.9 F)
1978
40.0 C (104.0 F)
1979
38.9 C (102.0 F)
1980
40.6 C (105.1 F)
1981
37.8 C (100.0 F)
1982
37.8 C (100.0 F)
1983
40.6 C (105.1 F)
1984
36.7 C (98.1 F)
1985
37.8 C (100.0 F)
1986
37.8 C (100.0 F)
1987
37.8 C (100.0 F)
1988
38.9 C (102.0 F)
1989
39.4 C (102.9 F)
1990
40.6 C (105.1 F)
1991
38.3 C (100.9 F)
1992
38.3 C (100.9 F)
1993
36.1 C (97.0 F)
1994
40.0 C (104.0 F)
1995
36.7 C (98.1 F)
1996
38.9 C (102.0 F)
1997
38.9 C (102.0 F)
1998
41.1 C (106.0 F)
1999
38.9 C (102.0 F)
2000
43.9 C (111.0 F)
2002
32.8 C (91.0 F)
2003
41.1 C (106.0 F)
2004
37.8 C (100.0 F)
2005
37.8 C (100.0 F)
2006
37.8 C (100.0 F)
Coldest night (TNn)
The coldest night of the year at Anderson Dam, 1942 to 2006. The record is -29.4 C (-20.9 F) in 1949, marked on the chart; the median year is -20.3 C (-4.5 F).
Coldest night (TNn) at Anderson Dam by year
Year
Coldest night (TNn)
1942
-25.6 C (-14.1 F)
1943
-27.8 C (-18.0 F)
1944
-20.6 C (-5.1 F)
1945
-20.0 C (-4.0 F)
1946
-21.7 C (-7.1 F)
1947
-27.2 C (-17.0 F)
1948
-25.6 C (-14.1 F)
1949
-29.4 C (-20.9 F)
1950
-26.1 C (-15.0 F)
1951
-24.4 C (-11.9 F)
1952
-25.0 C (-13.0 F)
1953
-12.8 C (9.0 F)
1954
-15.0 C (5.0 F)
1955
-20.0 C (-4.0 F)
1956
-26.7 C (-16.1 F)
1957
-26.7 C (-16.1 F)
1958
-13.3 C (8.1 F)
1959
-19.4 C (-2.9 F)
1960
-18.3 C (-0.9 F)
1961
-18.9 C (-2.0 F)
1962
-29.4 C (-20.9 F)
1963
-21.7 C (-7.1 F)
1964
-22.2 C (-8.0 F)
1965
-15.0 C (5.0 F)
1966
-13.9 C (7.0 F)
1967
-17.8 C (0.0 F)
1968
-15.0 C (5.0 F)
1969
-17.2 C (1.0 F)
1970
-17.2 C (1.0 F)
1971
-22.2 C (-8.0 F)
1972
-25.0 C (-13.0 F)
1973
-14.4 C (6.1 F)
1974
-21.7 C (-7.1 F)
1975
-17.8 C (0.0 F)
1976
-17.2 C (1.0 F)
1977
-15.0 C (5.0 F)
1978
-21.7 C (-7.1 F)
1979
-23.3 C (-9.9 F)
1980
-21.7 C (-7.1 F)
1981
-13.9 C (7.0 F)
1982
-20.6 C (-5.1 F)
1983
-26.1 C (-15.0 F)
1984
-25.6 C (-14.1 F)
1985
-23.9 C (-11.0 F)
1986
-13.9 C (7.0 F)
1987
-18.3 C (-0.9 F)
1988
-23.3 C (-9.9 F)
1989
-28.9 C (-20.0 F)
1990
-28.3 C (-18.9 F)
1991
-16.7 C (1.9 F)
1992
-18.9 C (-2.0 F)
1993
-25.6 C (-14.1 F)
1994
-17.8 C (0.0 F)
1995
-18.9 C (-2.0 F)
1996
-23.3 C (-9.9 F)
1997
-20.6 C (-5.1 F)
1998
-18.3 C (-0.9 F)
1999
-16.1 C (3.0 F)
2000
-12.8 C (9.0 F)
2002
-16.1 C (3.0 F)
2003
-12.2 C (10.0 F)
2004
-17.8 C (0.0 F)
2005
-17.2 C (1.0 F)
2006
-21.7 C (-7.1 F)
Wettest day (Rx1day)
The wettest day of the year at Anderson Dam, 1942 to 2006. The record is 58.7 mm (2.3 in) in 2004, marked on the chart; the median year is 35.7 mm (1.4 in).
Wettest day (Rx1day) at Anderson Dam by year
Year
Wettest day (Rx1day)
1942
44.5 mm (1.8 in)
1943
43.7 mm (1.7 in)
1944
24.9 mm (1.0 in)
1945
43.2 mm (1.7 in)
1946
23.9 mm (0.9 in)
1947
27.2 mm (1.1 in)
1948
29.2 mm (1.1 in)
1949
24.4 mm (1.0 in)
1950
40.6 mm (1.6 in)
1951
35.8 mm (1.4 in)
1952
40.6 mm (1.6 in)
1953
41.9 mm (1.6 in)
1954
29.5 mm (1.2 in)
1955
45.2 mm (1.8 in)
1956
35.6 mm (1.4 in)
1957
42.2 mm (1.7 in)
1958
27.4 mm (1.1 in)
1959
46.2 mm (1.8 in)
1960
51.6 mm (2.0 in)
1961
39.1 mm (1.5 in)
1962
28.7 mm (1.1 in)
1963
41.4 mm (1.6 in)
1964
55.4 mm (2.2 in)
1965
42.9 mm (1.7 in)
1966
25.1 mm (1.0 in)
1967
34.0 mm (1.3 in)
1968
48.5 mm (1.9 in)
1969
33.3 mm (1.3 in)
1970
52.6 mm (2.1 in)
1971
41.7 mm (1.6 in)
1972
37.1 mm (1.5 in)
1973
21.6 mm (0.9 in)
1974
28.4 mm (1.1 in)
1975
37.3 mm (1.5 in)
1976
33.8 mm (1.3 in)
1977
26.2 mm (1.0 in)
1978
26.9 mm (1.1 in)
1979
27.4 mm (1.1 in)
1980
50.8 mm (2.0 in)
1981
42.7 mm (1.7 in)
1982
38.1 mm (1.5 in)
1983
33.3 mm (1.3 in)
1984
43.9 mm (1.7 in)
1985
46.5 mm (1.8 in)
1986
29.2 mm (1.1 in)
1987
24.4 mm (1.0 in)
1988
35.1 mm (1.4 in)
1989
34.5 mm (1.4 in)
1990
15.0 mm (0.6 in)
1991
31.2 mm (1.2 in)
1992
33.3 mm (1.3 in)
1993
33.5 mm (1.3 in)
1994
24.1 mm (0.9 in)
1995
38.6 mm (1.5 in)
1996
41.9 mm (1.6 in)
1997
37.6 mm (1.5 in)
1998
35.3 mm (1.4 in)
1999
39.1 mm (1.5 in)
2000
50.0 mm (2.0 in)
2002
31.8 mm (1.3 in)
2003
28.4 mm (1.1 in)
2004
58.7 mm (2.3 in)
2005
32.8 mm (1.3 in)
2006
38.1 mm (1.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Anderson Dam, 1942 to 2006. The record is 150.1 mm (5.9 in) in 1964, marked on the chart; the median year is 58.5 mm (2.3 in).
Wettest five days (Rx5day) at Anderson Dam by year
Year
Wettest five days (Rx5day)
1942
112.5 mm (4.4 in)
1943
70.5 mm (2.8 in)
1944
55.4 mm (2.2 in)
1945
79.3 mm (3.1 in)
1946
46.3 mm (1.8 in)
1947
32.8 mm (1.3 in)
1948
53.8 mm (2.1 in)
1949
52.1 mm (2.1 in)
1950
75.4 mm (3.0 in)
1951
76.2 mm (3.0 in)
1952
75.4 mm (3.0 in)
1953
59.2 mm (2.3 in)
1954
49.6 mm (2.0 in)
1955
99.1 mm (3.9 in)
1956
57.2 mm (2.3 in)
1957
56.7 mm (2.2 in)
1958
51.8 mm (2.0 in)
1959
63.7 mm (2.5 in)
1960
80.8 mm (3.2 in)
1961
58.0 mm (2.3 in)
1962
51.8 mm (2.0 in)
1963
104.1 mm (4.1 in)
1964
150.1 mm (5.9 in)
1965
62.5 mm (2.5 in)
1966
54.9 mm (2.2 in)
1967
69.4 mm (2.7 in)
1968
81.6 mm (3.2 in)
1969
74.0 mm (2.9 in)
1970
86.7 mm (3.4 in)
1971
111.8 mm (4.4 in)
1972
102.9 mm (4.1 in)
1973
64.5 mm (2.5 in)
1974
51.8 mm (2.0 in)
1975
83.7 mm (3.3 in)
1976
58.4 mm (2.3 in)
1977
81.9 mm (3.2 in)
1978
66.8 mm (2.6 in)
1979
58.5 mm (2.3 in)
1980
75.6 mm (3.0 in)
1981
70.7 mm (2.8 in)
1982
65.8 mm (2.6 in)
1983
43.9 mm (1.7 in)
1984
68.9 mm (2.7 in)
1985
57.2 mm (2.3 in)
1986
39.1 mm (1.5 in)
1987
38.7 mm (1.5 in)
1988
48.8 mm (1.9 in)
1989
16.3 mm (0.6 in)
1990
22.3 mm (0.9 in)
1991
25.6 mm (1.0 in)
1992
43.2 mm (1.7 in)
1993
76.7 mm (3.0 in)
1994
52.6 mm (2.1 in)
1995
50.7 mm (2.0 in)
1996
76.7 mm (3.0 in)
1997
48.3 mm (1.9 in)
1998
18.8 mm (0.7 in)
1999
39.9 mm (1.6 in)
2000
30.5 mm (1.2 in)
2002
30.2 mm (1.2 in)
2003
61.0 mm (2.4 in)
2004
58.7 mm (2.3 in)
2005
38.6 mm (1.5 in)
2006
15.2 mm (0.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Anderson Dam, 1942 to 2006. The record is 100 days in 1944, marked on the chart; the median year is 45 days.
Longest dry spell (CDD) at Anderson Dam by year
Year
Longest dry spell (CDD)
1942
72 days
1943
97 days
1944
100 days
1945
53 days
1946
36 days
1947
42 days
1948
64 days
1949
74 days
1950
33 days
1951
38 days
1952
63 days
1953
64 days
1954
35 days
1955
69 days
1956
70 days
1957
78 days
1958
57 days
1959
31 days
1960
66 days
1961
28 days
1962
40 days
1963
29 days
1964
58 days
1965
28 days
1966
60 days
1967
54 days
1968
36 days
1969
65 days
1970
24 days
1971
48 days
1972
50 days
1973
42 days
1974
49 days
1975
22 days
1976
67 days
1977
48 days
1978
51 days
1979
30 days
1980
28 days
1981
79 days
1982
46 days
1983
27 days
1984
22 days
1985
36 days
1986
26 days
1987
79 days
1988
42 days
1989
32 days
1990
22 days
1991
45 days
1992
50 days
1993
35 days
1994
60 days
1995
25 days
1996
45 days
1997
24 days
1998
30 days
1999
59 days
2000
44 days
2002
46 days
2003
39 days
2004
27 days
2005
38 days
2006
13 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.
Frost Dates and Growing Season
32 years with a frost
Across 32 years with a frost, the median last spring frost at Anderson Dam falls on 5 May and the median first autumn frost on 6 October, which leaves a median of 153 days between them.
Fitted over all years, the growing season changes by +1.1 days per decade at this station.
Frost dates and growing season at Anderson Dam
Measure
Median, all years
Earliest period
Recent period (1945 to 1978)
Recent against earliest
Fitted trend
Last spring frost
5 May
n/a
4 May
n/a
+0.7 days per decade
First autumn frost
6 October
n/a
7 October
n/a
+1.9 days per decade
Growing days
153 days
n/a
154 days
n/a
+1.1 days per decade
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
40 years, 1942 to 1981
A day with at least 36.5 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 58.9 mm (2.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Anderson Dam: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
36.5 mm (1.4 in)
5 years
44.8 mm (1.8 in)
10 years
49.2 mm (1.9 in)
25 years
53.8 mm (2.1 in)
50 years
56.6 mm (2.2 in)
Longer than the 40 years of record
100 years
58.9 mm (2.3 in)
Longer than the 40 years of record
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 40 years of values from 1942 to 1981.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 55.4 mm (2.2 in) in 1964; 52.6 mm (2.1 in) in 1970; 51.6 mm (2.0 in) in 1960.
Download the Data
Data for Anderson Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Anderson 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.