All-time weather records — Cortland, IL

Record high
102.9°F
August 17, 1988
Record low
-27.0°F
January 20, 1985
Wettest day
8.09 in
July 18, 1996

Climate change signal in Cortland

15.8%

of Cortland's all-time daily heat records were set in the last decade (58 of 366 records since 2015).

12.3%

of all-time daily cold records were set in the last decade (45 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
17
34
1970s
63
92
1980s
67
91
1990s
56
60
2000s
61
27
2010s
71
47
2020s
31
15

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 1966, the latest in 2026. Period of observation: 1966-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 63.0°F — Jan 24, 1967 -27.0°F — Jan 20, 1985 1.51 in — Jan 17, 2017
February 75.0°F — Feb 28, 2024 -26.0°F — Feb 1, 2019 2.60 in — Feb 21, 1997
March 84.0°F — Mar 30, 1986 -13.0°F — Mar 4, 2002 1.93 in — Mar 28, 2020
April 91.9°F — Apr 26, 1986 8.1°F — Apr 7, 1982 4.01 in — Apr 18, 2013
May 96.1°F — May 28, 2012 24.1°F — May 7, 1989 2.81 in — May 21, 2004
June 100.9°F — Jun 26, 1988 34.0°F — Jun 1, 1993 3.06 in — Jun 2, 1970
July 102.0°F — Jul 14, 1995 43.0°F — Jul 6, 1967 8.09 in — Jul 18, 1996
August 102.9°F — Aug 17, 1988 39.0°F — Aug 28, 1986 5.71 in — Aug 14, 1987
September 93.9°F — Sep 5, 2012 27.0°F — Sep 27, 1991 3.47 in — Sep 28, 1999
October 89.1°F — Oct 2, 1976 3.0°F — Oct 11, 1988 2.98 in — Oct 11, 1969
November 75.9°F — Nov 2, 2000 -8.0°F — Nov 29, 1976 2.20 in — Nov 11, 1995
December 69.1°F — Dec 4, 2012 -22.0°F — Dec 24, 1983 2.03 in — Dec 10, 2003

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