Record envelope, standing records and threshold days for Chief Joseph Dam (USC00451400), Washington, United States, with 72 years of record.
Key Facts for Chief Joseph Dam
Chief Joseph Dam (USC00451400) is a weather station in Washington, United States at 48.00 latitude and -119.65 longitude, 254 m (834 ft) above sea level.
The station reports from 1949 to 2020, 72 years of record.
1,464 records set at Chief Joseph Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Chief Joseph Dam set a daily record low maximum temperature of 4.4 C (39.9 F) on 25 October 2020.
About the Station
Location: Washington, United States, 48.00 latitude, -119.65 longitude.
Elevation: 254 m (834 ft).
Period of record: 1949 to 2020, 72 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 Chief Joseph 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 Chief Joseph Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.8 C (64.0 F)
-28.3 C (-18.9 F)
n/a
n/a
Feb
17.8 C (64.0 F)
-28.3 C (-18.9 F)
n/a
n/a
Mar
25.6 C (78.1 F)
-18.3 C (-0.9 F)
n/a
n/a
Apr
33.9 C (93.0 F)
-8.9 C (16.0 F)
n/a
n/a
May
39.4 C (102.9 F)
-8.3 C (17.1 F)
n/a
n/a
Jun
45.0 C (113.0 F)
-2.2 C (28.0 F)
n/a
n/a
Jul
43.3 C (109.9 F)
-0.6 C (30.9 F)
n/a
n/a
Aug
43.3 C (109.9 F)
1.7 C (35.1 F)
n/a
n/a
Sep
39.4 C (102.9 F)
-1.7 C (28.9 F)
n/a
n/a
Oct
32.8 C (91.0 F)
-12.2 C (10.0 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-22.8 C (-9.0 F)
n/a
n/a
Dec
15.0 C (59.0 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 Chief Joseph Dam still stand. 1985 holds the most, with 43.
Standing records at Chief Joseph Dam by the year they were set
Year set
Standing records
1949
4
1950
34
1951
25
1952
21
1953
19
1954
20
1955
36
1956
30
1957
25
1958
31
1959
14
1960
17
1961
11
1962
22
1963
20
1964
13
1965
13
1966
9
1967
25
1968
31
1969
13
1970
13
1971
23
1972
29
1973
14
1974
19
1975
24
1976
7
1977
21
1978
10
1979
22
1980
18
1981
25
1982
12
1983
24
1984
23
1985
43
1986
19
1987
34
1988
19
1989
18
1990
26
1991
18
1992
43
1993
19
1994
24
1995
18
1996
27
1997
22
1998
26
1999
17
2000
9
2001
6
2002
28
2003
20
2004
8
2005
15
2006
15
2007
12
2008
20
2009
10
2010
18
2011
27
2012
21
2013
27
2014
23
2015
36
2016
13
2017
12
2018
18
2019
23
2020
13
All-Time Record Progression
9 new records
9 all-time records were set at Chief Joseph Dam between 21 June 1984 and 28 June 2015. Each dot is a new record.
When Chief Joseph Dam set new all-time records
Date
Kind
Detail
1984-06-21
Record daily precipitation
Record daily precipitation 31.5 mm (1.2 in)
1992-07-23
Record daily precipitation
Record daily precipitation 44.2 mm (1.7 in)
1992-08-13
Record high minimum temperature
Record high minimum temperature 22.2 C (72.0 F)
1994-07-21
Record high maximum temperature
Record high maximum temperature 43.3 C (109.9 F)
1996-07-13
Record high minimum temperature
Record high minimum temperature 25.6 C (78.1 F)
1996-07-27
Record high minimum temperature
Record high minimum temperature 26.1 C (79.0 F)
1996-08-10
Record high minimum temperature
Record high minimum temperature 27.2 C (81.0 F)
1996-12-29
Record daily snowfall
Record daily snowfall 25.4 cm (10.0 in)
2015-06-28
Record high maximum temperature
Record high maximum temperature 45.0 C (113.0 F)
Wettest Day of Each Month
Jul: 44.2 mm (1.7 in)
The wettest day on record for each calendar month at Chief Joseph Dam. The most was 44.2 mm (1.7 in) on 23 July 1992.
Record daily precipitation for each month at Chief Joseph Dam
Month
Record daily precipitation (mm)
Date
Jan
25.1 mm (1.0 in)
15 January 1968
Feb
25.4 mm (1.0 in)
3 February 1961
Mar
40.6 mm (1.6 in)
14 March 2008
Apr
20.1 mm (0.8 in)
14 April 1957
May
31.2 mm (1.2 in)
11 May 1967
Jun
31.5 mm (1.2 in)
21 June 1984
Jul
44.2 mm (1.7 in)
23 July 1992
Aug
27.2 mm (1.1 in)
23 August 1965
Sep
27.7 mm (1.1 in)
20 September 2019
Oct
26.7 mm (1.1 in)
14 October 2016
Nov
29.5 mm (1.2 in)
11 November 1983
Dec
38.4 mm (1.5 in)
20 December 2016
Period of Record Coverage
1949 to 2020
Complete yearUnder 90 percent of days
72 years of record at Chief Joseph Dam, 1949 to 2020. 6 years have data for under 90 percent of days and are left out of rankings: 1949, 1950, 1954, 1973, 2017, 2020.
Cooler than the station meanWarmer than the station mean
One stripe for each of 57 complete years at Chief Joseph Dam, 1951 to 2019. Blue stripes are years cooler than the station's own mean of 10.3 C (50.5 F); red stripes are warmer. The coolest year was 1955, at 8.2 C (46.8 F), and the warmest was 1998, at 12.0 C (53.6 F). The strongest colour marks a difference of 2.2 C (4.0 F).
Annual mean temperature at Chief Joseph Dam as warming stripes, 1951 to 2019
Year
Annual mean temperature
Difference from the station mean
1951
9.2 C
-1.11 C
1952
9.3 C
-1.03 C
1953
10.9 C
+0.56 C
1955
8.2 C
-2.10 C
1957
9.7 C
-0.59 C
1958
11.7 C
+1.40 C
1959
9.6 C
-0.68 C
1960
10.1 C
-0.24 C
1961
10.6 C
+0.31 C
1962
10.4 C
+0.05 C
1963
10.8 C
+0.45 C
1965
10.4 C
+0.11 C
1966
10.5 C
+0.23 C
1967
11.4 C
+1.08 C
1968
10.0 C
-0.34 C
1969
9.2 C
-1.06 C
1970
9.7 C
-0.58 C
1971
9.1 C
-1.19 C
1974
10.4 C
+0.12 C
1975
9.2 C
-1.08 C
1976
9.9 C
-0.41 C
1978
9.9 C
-0.42 C
1979
10.3 C
+0.04 C
1980
9.7 C
-0.65 C
1981
11.0 C
+0.67 C
1982
9.6 C
-0.67 C
1983
10.3 C
-0.05 C
1984
9.3 C
-1.01 C
1985
8.8 C
-1.50 C
1986
11.0 C
+0.65 C
1987
11.9 C
+1.55 C
1988
11.2 C
+0.89 C
1989
10.8 C
+0.51 C
1990
11.4 C
+1.05 C
1992
11.6 C
+1.31 C
1993
9.2 C
-1.14 C
1994
10.6 C
+0.26 C
1995
11.1 C
+0.82 C
1996
9.5 C
-0.84 C
1998
12.0 C
+1.69 C
1999
10.8 C
+0.53 C
2000
9.9 C
-0.36 C
2001
10.8 C
+0.48 C
2002
10.7 C
+0.35 C
2003
11.1 C
+0.81 C
2004
11.5 C
+1.16 C
2005
10.6 C
+0.33 C
2006
10.9 C
+0.56 C
2007
10.4 C
+0.12 C
2009
9.8 C
-0.52 C
2010
10.0 C
-0.32 C
2011
9.0 C
-1.26 C
2012
10.5 C
+0.19 C
2013
9.9 C
-0.40 C
2014
11.0 C
+0.72 C
2016
11.2 C
+0.85 C
2019
10.1 C
-0.23 C
The fitted trend in annual mean temperature here over 1951 to 2019 is 0.11 C (0.00 to 0.22) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.20 F (0.00 to 0.40) per decade. The slope is a straight line fitted to 57 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Chief Joseph Dam
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.11 C (0.00 to 0.22) per decade
0.20 F (0.00 to 0.40) per decade
1951 to 2019
57
Not clearly different from zero
Mean daily maximum
0.17 C (0.04 to 0.29) per decade
0.3 F (0.1 to 0.5) per decade
1951 to 2019
57
Rise
Mean daily minimum
0.1 C (-0.1 to 0.2) per decade
0.1 F (-0.1 to 0.3) per decade
1951 to 2019
57
Not clearly different from zero
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
1949 to 2020
Yearly extremes at Chief Joseph Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.0 C (113.0 F)
2015
40.0 C (104.0 F)
72
Coldest night (TNn)
-28.3 C (-18.9 F)
1950
-18.3 C (-0.9 F)
72
Wettest day (Rx1day)
44.2 mm (1.7 in)
1992
20.3 mm (0.8 in)
72
Wettest five days (Rx5day)
61.4 mm (2.4 in)
2016
34.1 mm (1.3 in)
72
Longest dry spell (CDD)
136 days
1961
52 days
72
Hottest day (TXx)
The hottest day of the year at Chief Joseph Dam, 1949 to 2020. The record is 45.0 C (113.0 F) in 2015, marked on the chart; the median year is 40.0 C (104.0 F).
Hottest day (TXx) at Chief Joseph Dam by year
Year
Hottest day (TXx)
1949
23.9 C (75.0 F)
1950
40.0 C (104.0 F)
1951
39.4 C (102.9 F)
1952
40.0 C (104.0 F)
1953
38.9 C (102.0 F)
1954
37.2 C (99.0 F)
1955
40.6 C (105.1 F)
1956
40.0 C (104.0 F)
1957
37.2 C (99.0 F)
1958
40.6 C (105.1 F)
1959
41.1 C (106.0 F)
1960
42.2 C (108.0 F)
1961
42.2 C (108.0 F)
1962
38.3 C (100.9 F)
1963
36.7 C (98.1 F)
1964
37.8 C (100.0 F)
1965
38.3 C (100.9 F)
1966
39.4 C (102.9 F)
1967
39.4 C (102.9 F)
1968
40.0 C (104.0 F)
1969
37.8 C (100.0 F)
1970
38.9 C (102.0 F)
1971
38.9 C (102.0 F)
1972
38.9 C (102.0 F)
1973
40.0 C (104.0 F)
1974
37.2 C (99.0 F)
1975
41.7 C (107.1 F)
1976
37.2 C (99.0 F)
1977
41.7 C (107.1 F)
1978
39.4 C (102.9 F)
1979
42.2 C (108.0 F)
1980
40.0 C (104.0 F)
1981
41.7 C (107.1 F)
1982
39.4 C (102.9 F)
1983
38.9 C (102.0 F)
1984
39.4 C (102.9 F)
1985
41.1 C (106.0 F)
1986
41.1 C (106.0 F)
1987
40.0 C (104.0 F)
1988
40.0 C (104.0 F)
1989
38.9 C (102.0 F)
1990
41.1 C (106.0 F)
1991
38.9 C (102.0 F)
1992
42.2 C (108.0 F)
1993
37.2 C (99.0 F)
1994
43.3 C (109.9 F)
1995
39.4 C (102.9 F)
1996
41.1 C (106.0 F)
1997
40.0 C (104.0 F)
1998
43.3 C (109.9 F)
1999
38.9 C (102.0 F)
2000
40.0 C (104.0 F)
2001
39.4 C (102.9 F)
2002
42.2 C (108.0 F)
2003
41.1 C (106.0 F)
2004
40.6 C (105.1 F)
2005
38.9 C (102.0 F)
2006
43.3 C (109.9 F)
2007
40.6 C (105.1 F)
2008
41.1 C (106.0 F)
2009
41.7 C (107.1 F)
2010
38.3 C (100.9 F)
2011
37.2 C (99.0 F)
2012
40.6 C (105.1 F)
2013
40.6 C (105.1 F)
2014
41.7 C (107.1 F)
2015
45.0 C (113.0 F)
2016
38.9 C (102.0 F)
2017
40.6 C (105.1 F)
2018
40.6 C (105.1 F)
2019
40.6 C (105.1 F)
2020
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at Chief Joseph Dam, 1949 to 2020. The record is -28.3 C (-18.9 F) in 1950, marked on the chart; the median year is -18.3 C (-0.9 F).
Coldest night (TNn) at Chief Joseph Dam by year
Year
Coldest night (TNn)
1949
-17.2 C (1.0 F)
1950
-28.3 C (-18.9 F)
1951
-20.0 C (-4.0 F)
1952
-23.3 C (-9.9 F)
1953
-7.8 C (18.0 F)
1954
-22.2 C (-8.0 F)
1955
-18.3 C (-0.9 F)
1956
-24.4 C (-11.9 F)
1957
-23.9 C (-11.0 F)
1958
-14.4 C (6.1 F)
1959
-19.4 C (-2.9 F)
1960
-20.0 C (-4.0 F)
1961
-15.0 C (5.0 F)
1962
-18.3 C (-0.9 F)
1963
-16.1 C (3.0 F)
1964
-23.3 C (-9.9 F)
1965
-13.3 C (8.1 F)
1966
-15.0 C (5.0 F)
1967
-17.8 C (0.0 F)
1968
-28.3 C (-18.9 F)
1969
-26.1 C (-15.0 F)
1970
-17.2 C (1.0 F)
1971
-20.0 C (-4.0 F)
1972
-22.2 C (-8.0 F)
1973
-17.8 C (0.0 F)
1974
-19.4 C (-2.9 F)
1975
-17.8 C (0.0 F)
1976
-15.0 C (5.0 F)
1977
-16.1 C (3.0 F)
1978
-23.3 C (-9.9 F)
1979
-25.0 C (-13.0 F)
1980
-25.0 C (-13.0 F)
1981
-12.2 C (10.0 F)
1982
-22.2 C (-8.0 F)
1983
-24.4 C (-11.9 F)
1984
-20.6 C (-5.1 F)
1985
-26.1 C (-15.0 F)
1986
-20.0 C (-4.0 F)
1987
-13.3 C (8.1 F)
1988
-16.7 C (1.9 F)
1989
-21.7 C (-7.1 F)
1990
-20.6 C (-5.1 F)
1991
-17.2 C (1.0 F)
1992
-15.6 C (3.9 F)
1993
-22.2 C (-8.0 F)
1994
-13.3 C (8.1 F)
1995
-13.9 C (7.0 F)
1996
-24.4 C (-11.9 F)
1997
-18.3 C (-0.9 F)
1998
-17.2 C (1.0 F)
1999
-10.6 C (12.9 F)
2000
-14.4 C (6.1 F)
2001
-12.8 C (9.0 F)
2002
-12.2 C (10.0 F)
2003
-13.3 C (8.1 F)
2004
-20.0 C (-4.0 F)
2005
-21.7 C (-7.1 F)
2006
-18.3 C (-0.9 F)
2007
-16.7 C (1.9 F)
2008
-19.4 C (-2.9 F)
2009
-20.0 C (-4.0 F)
2010
-21.7 C (-7.1 F)
2011
-25.0 C (-13.0 F)
2012
-16.1 C (3.0 F)
2013
-17.8 C (0.0 F)
2014
-22.2 C (-8.0 F)
2015
-15.6 C (3.9 F)
2016
-20.0 C (-4.0 F)
2017
-21.7 C (-7.1 F)
2018
-15.0 C (5.0 F)
2019
-18.3 C (-0.9 F)
2020
-13.9 C (7.0 F)
Wettest day (Rx1day)
The wettest day of the year at Chief Joseph Dam, 1949 to 2020. The record is 44.2 mm (1.7 in) in 1992, marked on the chart; the median year is 20.3 mm (0.8 in).
Wettest day (Rx1day) at Chief Joseph Dam by year
Year
Wettest day (Rx1day)
1949
8.9 mm (0.35 in)
1950
16.5 mm (0.6 in)
1951
26.7 mm (1.1 in)
1952
29.2 mm (1.1 in)
1953
21.1 mm (0.8 in)
1954
13.0 mm (0.5 in)
1955
18.8 mm (0.7 in)
1956
25.7 mm (1.0 in)
1957
20.1 mm (0.8 in)
1958
14.5 mm (0.6 in)
1959
17.5 mm (0.7 in)
1960
19.1 mm (0.8 in)
1961
25.4 mm (1.0 in)
1962
17.8 mm (0.7 in)
1963
17.8 mm (0.7 in)
1964
13.2 mm (0.5 in)
1965
27.2 mm (1.1 in)
1966
16.8 mm (0.7 in)
1967
31.2 mm (1.2 in)
1968
25.1 mm (1.0 in)
1969
18.3 mm (0.7 in)
1970
18.8 mm (0.7 in)
1971
16.0 mm (0.6 in)
1972
16.0 mm (0.6 in)
1973
22.9 mm (0.9 in)
1974
21.6 mm (0.9 in)
1975
26.4 mm (1.0 in)
1976
19.3 mm (0.8 in)
1977
17.0 mm (0.7 in)
1978
23.9 mm (0.9 in)
1979
17.3 mm (0.7 in)
1980
20.3 mm (0.8 in)
1981
21.3 mm (0.8 in)
1982
16.0 mm (0.6 in)
1983
29.5 mm (1.2 in)
1984
31.5 mm (1.2 in)
1985
13.5 mm (0.5 in)
1986
21.6 mm (0.9 in)
1987
26.4 mm (1.0 in)
1988
25.4 mm (1.0 in)
1989
25.4 mm (1.0 in)
1990
19.3 mm (0.8 in)
1991
27.4 mm (1.1 in)
1992
44.2 mm (1.7 in)
1993
30.0 mm (1.2 in)
1994
19.8 mm (0.8 in)
1995
20.3 mm (0.8 in)
1996
27.9 mm (1.1 in)
1997
23.9 mm (0.9 in)
1998
19.8 mm (0.8 in)
1999
16.5 mm (0.6 in)
2000
17.5 mm (0.7 in)
2001
16.5 mm (0.6 in)
2002
17.0 mm (0.7 in)
2003
18.3 mm (0.7 in)
2004
20.6 mm (0.8 in)
2005
30.5 mm (1.2 in)
2006
24.1 mm (0.9 in)
2007
22.9 mm (0.9 in)
2008
40.6 mm (1.6 in)
2009
15.2 mm (0.6 in)
2010
21.1 mm (0.8 in)
2011
20.8 mm (0.8 in)
2012
18.3 mm (0.7 in)
2013
14.5 mm (0.6 in)
2014
21.8 mm (0.9 in)
2015
17.8 mm (0.7 in)
2016
38.4 mm (1.5 in)
2017
20.1 mm (0.8 in)
2018
21.6 mm (0.9 in)
2019
27.7 mm (1.1 in)
2020
15.0 mm (0.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Chief Joseph Dam, 1949 to 2020. The record is 61.4 mm (2.4 in) in 2016, marked on the chart; the median year is 34.1 mm (1.3 in).
Wettest five days (Rx5day) at Chief Joseph Dam by year
Year
Wettest five days (Rx5day)
1949
17.1 mm (0.7 in)
1950
20.6 mm (0.8 in)
1951
43.0 mm (1.7 in)
1952
40.6 mm (1.6 in)
1953
21.1 mm (0.8 in)
1954
23.4 mm (0.9 in)
1955
38.4 mm (1.5 in)
1956
36.1 mm (1.4 in)
1957
29.5 mm (1.2 in)
1958
23.3 mm (0.9 in)
1959
26.4 mm (1.0 in)
1960
33.3 mm (1.3 in)
1961
50.1 mm (2.0 in)
1962
39.4 mm (1.6 in)
1963
31.5 mm (1.2 in)
1964
21.3 mm (0.8 in)
1965
46.8 mm (1.8 in)
1966
32.1 mm (1.3 in)
1967
34.0 mm (1.3 in)
1968
53.9 mm (2.1 in)
1969
40.4 mm (1.6 in)
1970
30.3 mm (1.2 in)
1971
31.7 mm (1.2 in)
1972
26.9 mm (1.1 in)
1973
45.8 mm (1.8 in)
1974
30.4 mm (1.2 in)
1975
29.4 mm (1.2 in)
1976
28.2 mm (1.1 in)
1977
30.7 mm (1.2 in)
1978
34.3 mm (1.4 in)
1979
23.7 mm (0.9 in)
1980
33.0 mm (1.3 in)
1981
34.8 mm (1.4 in)
1982
39.7 mm (1.6 in)
1983
49.3 mm (1.9 in)
1984
44.7 mm (1.8 in)
1985
18.3 mm (0.7 in)
1986
51.9 mm (2.0 in)
1987
43.2 mm (1.7 in)
1988
31.5 mm (1.2 in)
1989
39.1 mm (1.5 in)
1990
34.1 mm (1.3 in)
1991
41.7 mm (1.6 in)
1992
51.1 mm (2.0 in)
1993
38.1 mm (1.5 in)
1994
26.2 mm (1.0 in)
1995
49.3 mm (1.9 in)
1996
57.7 mm (2.3 in)
1997
59.2 mm (2.3 in)
1998
45.8 mm (1.8 in)
1999
31.7 mm (1.2 in)
2000
22.2 mm (0.9 in)
2001
33.8 mm (1.3 in)
2002
37.3 mm (1.5 in)
2003
39.1 mm (1.5 in)
2004
49.5 mm (1.9 in)
2005
41.7 mm (1.6 in)
2006
42.9 mm (1.7 in)
2007
40.7 mm (1.6 in)
2008
47.3 mm (1.9 in)
2009
20.4 mm (0.8 in)
2010
25.7 mm (1.0 in)
2011
24.9 mm (1.0 in)
2012
28.5 mm (1.1 in)
2013
16.8 mm (0.7 in)
2014
37.3 mm (1.5 in)
2015
25.9 mm (1.0 in)
2016
61.4 mm (2.4 in)
2017
34.8 mm (1.4 in)
2018
26.4 mm (1.0 in)
2019
30.7 mm (1.2 in)
2020
26.5 mm (1.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Chief Joseph Dam, 1949 to 2020. The record is 136 days in 1961, marked on the chart; the median year is 52 days.
Longest dry spell (CDD) at Chief Joseph Dam by year
Year
Longest dry spell (CDD)
1949
19 days
1950
77 days
1951
52 days
1952
62 days
1953
52 days
1954
51 days
1955
49 days
1956
45 days
1957
42 days
1958
33 days
1959
77 days
1960
69 days
1961
136 days
1962
46 days
1963
69 days
1964
62 days
1965
71 days
1966
54 days
1967
85 days
1968
72 days
1969
81 days
1970
54 days
1971
53 days
1972
33 days
1973
51 days
1974
55 days
1975
37 days
1976
51 days
1977
49 days
1978
46 days
1979
43 days
1980
48 days
1981
62 days
1982
25 days
1983
27 days
1984
37 days
1985
73 days
1986
70 days
1987
77 days
1988
75 days
1989
57 days
1990
52 days
1991
78 days
1992
47 days
1993
62 days
1994
47 days
1995
26 days
1996
45 days
1997
31 days
1998
41 days
1999
57 days
2000
108 days
2001
36 days
2002
50 days
2003
86 days
2004
32 days
2005
46 days
2006
93 days
2007
71 days
2008
37 days
2009
38 days
2010
32 days
2011
56 days
2012
72 days
2013
50 days
2014
48 days
2015
67 days
2016
19 days
2017
25 days
2018
75 days
2019
38 days
2020
100 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
57 years with a frost
Across 57 years with a frost, the median last spring frost at Chief Joseph Dam falls on 21 April and the median first autumn frost on 11 October, which leaves a median of 172 days between them.
Fitted over all years, the growing season changes by -2.7 days per decade at this station.
Frost dates and growing season at Chief Joseph Dam
Measure
Median, all years
Earliest period
Recent period (1984 to 2019)
Recent against earliest
Fitted trend
Last spring frost
21 April
n/a
22 April
n/a
+1.0 days per decade
First autumn frost
11 October
n/a
10 October
n/a
-1.7 days per decade
Growing days
172 days
n/a
173 days
n/a
-2.7 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
65 years, 1950 to 2018
A day with at least 20.6 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 45.3 mm (1.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Chief Joseph 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
20.6 mm (0.8 in)
5 years
26.0 mm (1.0 in)
10 years
30.0 mm (1.2 in)
25 years
35.7 mm (1.4 in)
50 years
40.3 mm (1.6 in)
100 years
45.3 mm (1.8 in)
Longer than the 65 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, 65 years of values from 1950 to 2018.
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: 44.2 mm (1.7 in) in 1992; 40.6 mm (1.6 in) in 2008; 38.4 mm (1.5 in) in 2016.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Chief Joseph Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Chief Joseph 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.