All-time weather records — Grand Coulee, WA

Record high
113.0°F
July 27, 1939
Record low
-17.0°F
January 30, 1950
Wettest day
2.31 in
June 27, 1996

Climate change signal in Grand Coulee

8.7%

of Grand Coulee's all-time daily heat records were set in the last decade (32 of 366 records since 2015).

5.7%

of all-time daily cold records were set in the last decade (21 of 366 records since 2015).

If records were spread evenly across the station's history, you'd expect roughly 5% per decade. Decade-by-decade, here's where each record-breaking day was set:

Decade Heat records set # Cold records set #
1930s
102
21
1940s
59
34
1950s
16
71
1960s
31
41
1970s
29
44
1980s
35
58
1990s
21
17
2000s
32
51
2010s
20
17
2020s
21
12

Records are the all-time daily extremes that are still standing — each daily record can only be held by one year. The station's earliest hot record was set in 1934, the latest in 2025. Period of observation: 1934-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 61.0°F — Jan 22, 1981 -17.0°F — Jan 30, 1950 0.86 in — Jan 17, 1945
February 61.0°F — Feb 20, 1995 -15.0°F — Feb 1, 1950 0.97 in — Feb 17, 1940
March 73.9°F — Mar 23, 1939 -0.9°F — Mar 4, 2019 1.50 in — Mar 15, 2012
April 91.9°F — Apr 17, 1936 19.9°F — Apr 2, 1936 1.10 in — Apr 16, 2011
May 100.0°F — May 30, 1986 27.0°F — May 1, 1954 1.35 in — May 31, 1941
June 111.9°F — Jun 28, 2021 36.0°F — Jun 10, 2008 2.31 in — Jun 27, 1996
July 113.0°F — Jul 27, 1939 6.1°F — Jul 8, 1985 1.29 in — Jul 21, 1965
August 109.9°F — Aug 4, 1961 32.0°F — Aug 14, 1985 1.22 in — Aug 4, 1948
September 104.0°F — Sep 2, 1938 5.0°F — Sep 14, 2011 1.38 in — Sep 26, 1948
October 90.0°F — Oct 2, 1935 10.0°F — Oct 31, 1984 1.36 in — Oct 16, 2006
November 69.1°F — Nov 9, 1989 -9.9°F — Nov 30, 1985 1.12 in — Nov 12, 1973
December 66.0°F — Dec 1, 2021 -16.1°F — Dec 30, 1968 0.95 in — Dec 2, 1996

Click a month to see every daily record for that month in Grand Coulee.