Every state’s recordsIllinois Weather Records
9 official all-time records
The official all-time extremes for Illinois, as NOAA’s State Climate Extremes Committee lists them: from 117°F at East St. Louis to -38°F at Mt. Carroll.
| Record | Date | Where | Station | Status |
|---|
| 117°F | July 14, 1954 | East St. Louis | 112614 | E: Value is unchanged from previous extremes tables last updated by NCEI (formerly NCDC) between 1998 and 2006. Value exceeds all other valid values. |
This value exceeded the previous record of -36 degrees F, observed at Congerville on 5 January 1999.
Greatest 24-Hour Precipitation
| Record | Date | Where | Station | Status |
|---|
| 16.91 inches | July 18, 1996 | Aurora | 110338 | E: Value is unchanged from previous extremes tables last updated by NCEI (formerly NCDC) between 1998 and 2006. Value exceeds all other valid values. |
| Record | Date | Where | Station | Status |
|---|
| 36 inches | February 28, 1900 | Astoria | 110291 | N: Value is changed from extremes tables last updated by NCEI (formerly NCDC) between 1998 and 2006. Value exceeds all other valid values. |
On March 10, 2026, a long-lived supercell thunderstorm moved across the Kankakee River Valley, producing an outbreak of tornadoes and large hail across parts of Illinois and Indiana. This event notably included a record-breaking hailstone found in Kankakee, Illinois, which was officially measured at 6.603 inches in diameter, weighing 19.65 ounces. To learn more about this record stone, see the full report.
On March 10, 2026, a long-lived supercell thunderstorm moved across the Kankakee River Valley, producing an outbreak of tornadoes and large hail across parts of Illinois and Indiana. This event notably included a record-breaking hailstone found in Kankakee, Illinois, which was officially measured at 6.603 inches in diameter, weighing 19.65 ounces. To learn more about this record stone, see the full report.
| Record | Date | Where | Station | Status |
|---|
| 38.697 cubic inches | March 10, 2026 | Kankakee | | SA |
On March 10, 2026, a long-lived supercell thunderstorm moved across the Kankakee River Valley, producing an outbreak of tornadoes and large hail across parts of Illinois and Indiana. This event notably included a record-breaking hailstone found in Kankakee, Illinois, which was officially measured at 6.603 inches in diameter, weighing 19.65 ounces. To learn more about this record stone, see the full report.