All-time weather records — Keystone, SD

Record high
100.0°F
July 7, 1985
Record low
-38.0°F
January 19, 1963
Wettest day
6.30 in
June 10, 1972

Climate change signal in Keystone

14.2%

of Keystone's all-time daily heat records were set in the last decade (52 of 366 records since 2015).

11.5%

of all-time daily cold records were set in the last decade (42 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 #
1960s
50
66
1970s
68
66
1980s
82
73
1990s
50
65
2000s
47
35
2010s
35
30
2020s
34
31

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 1962, the latest in 2026. Period of observation: 1962-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 70.0°F — Jan 27, 2015 -38.0°F — Jan 19, 1963 0.60 in — Jan 30, 1971
February 68.0°F — Feb 21, 1982 -29.0°F — Feb 3, 1989 0.95 in — Mar 1, 2004
March 80.1°F — Mar 21, 2026 -16.1°F — Mar 1, 2014 1.74 in — Mar 16, 1963
April 84.9°F — Apr 22, 1989 -2.9°F — Apr 5, 2023 2.30 in — Apr 19, 2000
May 93.0°F — May 27, 1969 14.0°F — May 1, 1967 3.38 in — May 8, 1995
June 99.0°F — Jun 27, 1970 27.0°F — Jun 16, 1981 6.30 in — Jun 10, 1972
July 100.0°F — Jul 7, 1985 35.1°F — Jul 6, 1986 2.52 in — Jul 24, 1977
August 99.0°F — Aug 20, 1973 33.1°F — Aug 18, 1968 2.26 in — Aug 29, 1996
September 97.0°F — Sep 6, 1978 19.0°F — Sep 25, 1984 2.10 in — Sep 1, 1963
October 86.0°F — Oct 2, 2011 -4.0°F — Oct 26, 2020 2.63 in — Oct 12, 2023
November 75.0°F — Nov 5, 1975 -11.9°F — Nov 27, 1985 1.11 in — Nov 1, 2000
December 68.0°F — Dec 12, 2014 -31.0°F — Dec 21, 1983 0.65 in — Dec 25, 2016

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