All-time weather records — Lerna, IL
Climate change signal in Lerna
of Lerna's all-time daily heat records were set in the last decade (126 of 366 records since 2015).
of all-time daily cold records were set in the last decade (124 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 | # |
|---|---|---|---|---|
| 1990s | 32 | 19 | ||
| 2000s | 113 | 141 | ||
| 2010s | 149 | 136 | ||
| 2020s | 72 | 70 |
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 1998, the latest in 2026. Period of observation: 1998-2026.
Records by month
| Month | Hottest day | Coldest day | Wettest day |
|---|---|---|---|
| January | 66.0°F — Jan 7, 2008 | -13.9°F — Jan 6, 2014 | 2.45 in — Jan 11, 2020 |
| February | 73.9°F — Feb 24, 2000 | -12.8°F — Feb 7, 2014 | 2.14 in — Feb 11, 2009 |
| March | 86.0°F — Mar 22, 2026 | -5.8°F — Mar 6, 2015 | 2.15 in — Mar 30, 2022 |
| April | 87.1°F — Apr 30, 2007 | 22.1°F — Apr 2, 2013 | 4.10 in — Apr 3, 2018 |
| May | 93.9°F — May 28, 2018 | 30.9°F — May 3, 2005 | 3.10 in — May 12, 2002 |
| June | 118.9°F — Jun 20, 2002 | -0.8°F — Jun 1, 2011 | 4.70 in — Jun 10, 2018 |
| July | 106.0°F — Jul 7, 2012 | -0.8°F — Jul 22, 2008 | 3.65 in — Jul 9, 2024 |
| August | 99.0°F — Aug 2, 2012 | -0.8°F — Aug 12, 2009 | 2.67 in — Aug 15, 2016 |
| September | 99.0°F — Sep 1, 2011 | 34.0°F — Sep 25, 2001 | 3.95 in — Sep 10, 2000 |
| October | 91.9°F — Oct 1, 2019 | 24.3°F — Oct 21, 2018 | 3.30 in — Oct 11, 2019 |
| November | 79.0°F — Nov 1, 2016 | 3.2°F — Nov 12, 2019 | 1.68 in — Nov 18, 2003 |
| December | 71.1°F — Dec 4, 1998 | -9.0°F — Dec 14, 2025 | 2.84 in — Dec 26, 2015 |
Click a month to see every daily record for that month in Lerna.