Record envelope, standing records and threshold days for Sun Valley (USC00108906), Idaho, United States, with 36 years of record.
Key Facts for Sun Valley
Sun Valley (USC00108906) is a weather station in Idaho, United States at 43.70 latitude and -114.35 longitude, 1,823 m (5,980 ft) above sea level.
The station reports from 1937 to 1972, 36 years of record.
1,464 records set at Sun Valley still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Sun Valley set a daily record high minimum temperature of -1.7 C (28.9 F) on 19 December 1972.
About the Station
Location: Idaho, United States, 43.70 latitude, -114.35 longitude.
Elevation: 1,823 m (5,980 ft).
Period of record: 1937 to 1972, 36 years.
Eligible elements: tmax, tmin, prcp, snow.
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 Sun Valley. 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 Sun Valley, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
11.1 C (52.0 F)
-41.1 C (-42.0 F)
n/a
n/a
Feb
13.3 C (55.9 F)
-43.3 C (-45.9 F)
n/a
n/a
Mar
16.1 C (61.0 F)
-33.3 C (-27.9 F)
n/a
n/a
Apr
26.1 C (79.0 F)
-20.0 C (-4.0 F)
n/a
n/a
May
30.0 C (86.0 F)
-15.0 C (5.0 F)
n/a
n/a
Jun
33.9 C (93.0 F)
-8.3 C (17.1 F)
n/a
n/a
Jul
35.6 C (96.1 F)
-7.2 C (19.0 F)
n/a
n/a
Aug
35.6 C (96.1 F)
-8.9 C (16.0 F)
n/a
n/a
Sep
33.9 C (93.0 F)
-11.7 C (10.9 F)
n/a
n/a
Oct
29.4 C (84.9 F)
-19.4 C (-2.9 F)
n/a
n/a
Nov
20.6 C (69.1 F)
-31.7 C (-25.1 F)
n/a
n/a
Dec
15.6 C (60.1 F)
-38.3 C (-36.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Sun Valley still stand. 1944 holds the most, with 78.
Standing records at Sun Valley by the year they were set
Year set
Standing records
1937
32
1938
38
1939
52
1940
45
1941
33
1942
61
1943
74
1944
78
1945
43
1946
38
1947
35
1948
48
1949
63
1950
53
1951
36
1952
38
1953
23
1954
44
1955
36
1956
37
1957
17
1958
28
1959
28
1960
47
1961
29
1962
47
1963
43
1964
42
1965
21
1966
27
1967
28
1968
37
1969
34
1970
44
1971
24
1972
61
Wettest Day of Each Month
Dec: 57.9 mm (2.3 in)
The wettest day on record for each calendar month at Sun Valley. The most was 57.9 mm (2.3 in) on 11 December 1937.
Record daily precipitation for each month at Sun Valley
Month
Record daily precipitation (mm)
Date
Jan
44.7 mm (1.8 in)
20 January 1943
Feb
38.1 mm (1.5 in)
11 February 1959
Mar
35.1 mm (1.4 in)
1 March 1970
Apr
27.9 mm (1.1 in)
28 April 1951
May
32.8 mm (1.3 in)
12 May 1958
Jun
32.8 mm (1.3 in)
10 June 1963
Jul
38.1 mm (1.5 in)
30 July 1958
Aug
31.0 mm (1.2 in)
20 August 1968
Sep
36.3 mm (1.4 in)
9 September 1950
Oct
28.4 mm (1.1 in)
16 October 1947
Nov
35.6 mm (1.4 in)
19 November 1946
Dec
57.9 mm (2.3 in)
11 December 1937
Period of Record Coverage
1937 to 1972
Complete yearUnder 90 percent of days
36 years of record at Sun Valley, 1937 to 1972. 1 years have data for under 90 percent of days and are left out of rankings: 1937.
Cooler than the station meanWarmer than the station mean
One stripe for each of 33 complete years at Sun Valley, 1938 to 1972. Blue stripes are years cooler than the station's own mean of 3.3 C (38.0 F); red stripes are warmer. The coolest year was 1942, at 1.7 C (35.0 F), and the warmest was 1972, at 4.3 C (39.7 F). The strongest colour marks a difference of 1.7 C (3.1 F).
Annual mean temperature at Sun Valley as warming stripes, 1938 to 1972
Year
Annual mean temperature
Difference from the station mean
1938
3.6 C
+0.31 C
1939
4.3 C
+0.94 C
1940
4.2 C
+0.85 C
1941
3.1 C
-0.18 C
1942
1.7 C
-1.63 C
1945
2.8 C
-0.51 C
1946
3.2 C
-0.13 C
1947
3.8 C
+0.48 C
1948
2.5 C
-0.85 C
1949
3.3 C
+0.01 C
1950
3.3 C
+0.01 C
1951
2.3 C
-1.00 C
1952
2.4 C
-0.90 C
1953
4.1 C
+0.76 C
1954
3.7 C
+0.38 C
1955
2.5 C
-0.81 C
1956
2.6 C
-0.72 C
1957
2.9 C
-0.45 C
1958
3.8 C
+0.51 C
1959
3.3 C
-0.02 C
1960
2.6 C
-0.73 C
1961
3.6 C
+0.27 C
1962
3.3 C
-0.01 C
1963
4.1 C
+0.76 C
1964
2.2 C
-1.17 C
1965
3.0 C
-0.35 C
1966
3.4 C
+0.09 C
1967
4.1 C
+0.75 C
1968
4.0 C
+0.69 C
1969
4.2 C
+0.84 C
1970
4.0 C
+0.68 C
1971
3.5 C
+0.22 C
1972
4.3 C
+0.94 C
The fitted trend in annual mean temperature here over 1938 to 1972 is 0.2 C (-0.1 to 0.4) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.3 F (-0.1 to 0.7) per decade. The slope is a straight line fitted to 33 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Sun Valley
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.2 C (-0.1 to 0.4) per decade
0.3 F (-0.1 to 0.7) per decade
1938 to 1972
33
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.3 to 0.1) per decade
-0.2 F (-0.6 to 0.2) per decade
1938 to 1972
33
Not clearly different from zero
Mean daily minimum
0.43 C (0.04 to 0.81) per decade
0.8 F (0.1 to 1.5) per decade
1938 to 1972
33
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
1937 to 1972
Yearly extremes at Sun Valley: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
35.6 C (96.1 F)
1960
33.3 C (91.9 F)
36
Coldest night (TNn)
-43.3 C (-45.9 F)
1950
-32.2 C (-26.0 F)
36
Wettest day (Rx1day)
57.9 mm (2.3 in)
1937
29.2 mm (1.1 in)
36
Wettest five days (Rx5day)
169.2 mm (6.7 in)
1964
57.4 mm (2.3 in)
36
Longest dry spell (CDD)
75 days
1959
36 days
36
Hottest day (TXx)
The hottest day of the year at Sun Valley, 1937 to 1972. The record is 35.6 C (96.1 F) in 1960, marked on the chart; the median year is 33.3 C (91.9 F).
Hottest day (TXx) at Sun Valley by year
Year
Hottest day (TXx)
1937
33.9 C (93.0 F)
1938
31.7 C (89.1 F)
1939
35.0 C (95.0 F)
1940
35.0 C (95.0 F)
1941
32.8 C (91.0 F)
1942
33.9 C (93.0 F)
1943
35.0 C (95.0 F)
1944
31.1 C (88.0 F)
1945
32.2 C (90.0 F)
1946
34.4 C (93.9 F)
1947
33.3 C (91.9 F)
1948
32.2 C (90.0 F)
1949
33.9 C (93.0 F)
1950
33.3 C (91.9 F)
1951
33.9 C (93.0 F)
1952
31.1 C (88.0 F)
1953
32.8 C (91.0 F)
1954
33.3 C (91.9 F)
1955
33.9 C (93.0 F)
1956
32.8 C (91.0 F)
1957
31.1 C (88.0 F)
1958
32.8 C (91.0 F)
1959
34.4 C (93.9 F)
1960
35.6 C (96.1 F)
1961
35.6 C (96.1 F)
1962
32.2 C (90.0 F)
1963
32.2 C (90.0 F)
1964
32.8 C (91.0 F)
1965
32.2 C (90.0 F)
1966
33.3 C (91.9 F)
1967
33.3 C (91.9 F)
1968
34.4 C (93.9 F)
1969
35.0 C (95.0 F)
1970
32.8 C (91.0 F)
1971
33.3 C (91.9 F)
1972
33.3 C (91.9 F)
Coldest night (TNn)
The coldest night of the year at Sun Valley, 1937 to 1972. The record is -43.3 C (-45.9 F) in 1950, marked on the chart; the median year is -32.2 C (-26.0 F).
Coldest night (TNn) at Sun Valley by year
Year
Coldest night (TNn)
1937
-20.6 C (-5.1 F)
1938
-28.9 C (-20.0 F)
1939
-30.6 C (-23.1 F)
1940
-26.7 C (-16.1 F)
1941
-31.1 C (-24.0 F)
1942
-38.3 C (-36.9 F)
1943
-41.1 C (-42.0 F)
1944
-35.0 C (-31.0 F)
1945
-31.1 C (-24.0 F)
1946
-30.0 C (-22.0 F)
1947
-32.2 C (-26.0 F)
1948
-34.4 C (-29.9 F)
1949
-36.7 C (-34.1 F)
1950
-43.3 C (-45.9 F)
1951
-37.2 C (-35.0 F)
1952
-35.0 C (-31.0 F)
1953
-27.8 C (-18.0 F)
1954
-30.0 C (-22.0 F)
1955
-32.2 C (-26.0 F)
1956
-38.9 C (-38.0 F)
1957
-33.9 C (-29.0 F)
1958
-26.1 C (-15.0 F)
1959
-34.4 C (-29.9 F)
1960
-36.1 C (-33.0 F)
1961
-35.6 C (-32.1 F)
1962
-37.2 C (-35.0 F)
1963
-35.0 C (-31.0 F)
1964
-38.3 C (-36.9 F)
1965
-33.3 C (-27.9 F)
1966
-32.2 C (-26.0 F)
1967
-30.0 C (-22.0 F)
1968
-28.9 C (-20.0 F)
1969
-27.2 C (-17.0 F)
1970
-30.0 C (-22.0 F)
1971
-30.6 C (-23.1 F)
1972
-31.1 C (-24.0 F)
Wettest day (Rx1day)
The wettest day of the year at Sun Valley, 1937 to 1972. The record is 57.9 mm (2.3 in) in 1937, marked on the chart; the median year is 29.2 mm (1.1 in).
Wettest day (Rx1day) at Sun Valley by year
Year
Wettest day (Rx1day)
1937
57.9 mm (2.3 in)
1938
29.7 mm (1.2 in)
1939
24.4 mm (1.0 in)
1940
29.2 mm (1.1 in)
1941
46.5 mm (1.8 in)
1942
25.1 mm (1.0 in)
1943
44.7 mm (1.8 in)
1944
25.9 mm (1.0 in)
1945
36.8 mm (1.4 in)
1946
35.6 mm (1.4 in)
1947
28.4 mm (1.1 in)
1948
24.1 mm (0.9 in)
1949
26.7 mm (1.1 in)
1950
36.3 mm (1.4 in)
1951
27.9 mm (1.1 in)
1952
22.1 mm (0.9 in)
1953
19.1 mm (0.8 in)
1954
31.8 mm (1.3 in)
1955
50.8 mm (2.0 in)
1956
27.4 mm (1.1 in)
1957
29.2 mm (1.1 in)
1958
38.1 mm (1.5 in)
1959
51.1 mm (2.0 in)
1960
30.5 mm (1.2 in)
1961
23.6 mm (0.9 in)
1962
25.4 mm (1.0 in)
1963
33.0 mm (1.3 in)
1964
54.9 mm (2.2 in)
1965
25.9 mm (1.0 in)
1966
25.4 mm (1.0 in)
1967
29.2 mm (1.1 in)
1968
31.0 mm (1.2 in)
1969
26.9 mm (1.1 in)
1970
35.1 mm (1.4 in)
1971
20.3 mm (0.8 in)
1972
18.3 mm (0.7 in)
Wettest five days (Rx5day)
The wettest five days of the year at Sun Valley, 1937 to 1972. The record is 169.2 mm (6.7 in) in 1964, marked on the chart; the median year is 57.4 mm (2.3 in).
Wettest five days (Rx5day) at Sun Valley by year
Year
Wettest five days (Rx5day)
1937
89.7 mm (3.5 in)
1938
79.8 mm (3.1 in)
1939
31.0 mm (1.2 in)
1940
58.7 mm (2.3 in)
1941
73.8 mm (2.9 in)
1942
62.0 mm (2.4 in)
1943
143.8 mm (5.7 in)
1944
71.1 mm (2.8 in)
1945
64.3 mm (2.5 in)
1946
93.9 mm (3.7 in)
1947
29.4 mm (1.2 in)
1948
51.3 mm (2.0 in)
1949
47.8 mm (1.9 in)
1950
49.8 mm (2.0 in)
1951
49.4 mm (1.9 in)
1952
78.7 mm (3.1 in)
1953
42.2 mm (1.7 in)
1954
46.0 mm (1.8 in)
1955
153.9 mm (6.1 in)
1956
41.1 mm (1.6 in)
1957
49.0 mm (1.9 in)
1958
45.3 mm (1.8 in)
1959
59.5 mm (2.3 in)
1960
42.0 mm (1.7 in)
1961
39.3 mm (1.5 in)
1962
66.3 mm (2.6 in)
1963
74.6 mm (2.9 in)
1964
169.2 mm (6.7 in)
1965
56.1 mm (2.2 in)
1966
50.3 mm (2.0 in)
1967
50.0 mm (2.0 in)
1968
67.8 mm (2.7 in)
1969
72.7 mm (2.9 in)
1970
90.7 mm (3.6 in)
1971
55.3 mm (2.2 in)
1972
51.8 mm (2.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Sun Valley, 1937 to 1972. The record is 75 days in 1959, marked on the chart; the median year is 36 days.
Longest dry spell (CDD) at Sun Valley by year
Year
Longest dry spell (CDD)
1937
40 days
1938
28 days
1939
62 days
1940
35 days
1941
20 days
1942
45 days
1943
43 days
1944
44 days
1945
27 days
1946
31 days
1947
34 days
1948
39 days
1949
51 days
1950
36 days
1951
37 days
1952
68 days
1953
56 days
1954
42 days
1955
42 days
1956
36 days
1957
39 days
1958
26 days
1959
75 days
1960
29 days
1961
29 days
1962
32 days
1963
28 days
1964
36 days
1965
66 days
1966
40 days
1967
22 days
1968
29 days
1969
44 days
1970
30 days
1971
29 days
1972
25 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
33 years with a frost
Across 33 years with a frost, the median last spring frost at Sun Valley falls on 30 June and the median first autumn frost on 2 July, which leaves a median of 4 days between them.
Fitted over all years, the growing season changes by +1.5 days per decade at this station.
Frost dates and growing season at Sun Valley
Measure
Median, all years
Earliest period
Recent period (1941 to 1972)
Recent against earliest
Fitted trend
Last spring frost
30 June
n/a
30 June
n/a
-0.1 days per decade
First autumn frost
2 July
n/a
2 July
n/a
+1.4 days per decade
Growing days
4 days
n/a
3 days
n/a
+1.5 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
35 years, 1938 to 1972
A day with at least 29.0 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 65.9 mm (2.6 in) of rain is expected about once in 100 years.
Rainfall return levels at Sun Valley: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
29.0 mm (1.1 in)
5 years
36.9 mm (1.5 in)
10 years
42.9 mm (1.7 in)
25 years
51.3 mm (2.0 in)
50 years
58.3 mm (2.3 in)
Longer than the 35 years of record
100 years
65.9 mm (2.6 in)
Longer than the 35 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, 35 years of values from 1938 to 1972.
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: 54.9 mm (2.2 in) in 1964; 51.1 mm (2.0 in) in 1959; 50.8 mm (2.0 in) in 1955.
Download the Data
Data for Sun Valley standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Sun Valley 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.