Jefferson County weather alerts
There are no active weather alerts for Jefferson County, IL right now.
Since 2016 the National Weather Service has issued about 725 alerts that included Jefferson County, roughly 73 a year. The most common is the severe thunderstorm warning (125 from 2016 to 2025). The last tornado warning was issued on June 22, 2026. 32 tornadoes have touched down in the county since 1950.
Updated from the National Weather Service · lists refresh hourly; the live map loads current alerts directly from the NWS
No warnings, watches or advisories include Jefferson County at the moment. This page updates automatically when the National Weather Service issues one. Check neighboring Hamilton County, Marion County, Wayne County, Franklin County.
Jefferson County alert history
Alert events that included Jefferson County or its forecast zones, from the NWS warning archive.
| Alert type | 2016–2025 | 2026 | Last issued |
|---|---|---|---|
| Severe Thunderstorm Warning | 125 | 18 | August 22, 2026 |
| Dense Fog Advisory | 78 | 2 | March 6, 2026 |
| Wind Advisory | 60 | 5 | June 17, 2026 |
| Severe Thunderstorm Watch | 53 | 6 | July 26, 2026 |
| Tornado Watch | 50 | 6 | June 21, 2026 |
| Flood Watch | 48 | 5 | July 9, 2026 |
| Winter Weather Advisory | 48 | 0 | December 2, 2025 |
| Flood Advisory | 41 | 4 | August 17, 2026 |
| Heat Advisory | 34 | 10 | September 15, 2026 |
| Freeze Warning | 33 | 3 | November 8, 2026 |
| Frost Advisory | 27 | 1 | October 18, 2026 |
| Flash Flood Warning | 24 | 1 | June 27, 2026 |
| Freeze Watch | 15 | 1 | November 8, 2026 |
| Tornado Warning | 15 | 6 | June 22, 2026 |
| Cold Weather Advisory | 14 | 2 | January 31, 2026 |
| Extreme Heat Warning | 12 | 5 | September 1, 2026 |
| Winter Storm Warning | 12 | 1 | January 24, 2026 |
| Winter Storm Watch | 11 | 1 | January 24, 2026 |
| Flood Warning | 10 | 0 | April 6, 2025 |
| Red Flag Warning | 7 | 1 | March 29, 2026 |
| Extreme Heat Watch | 4 | 2 | September 1, 2026 |
| High Wind Warning | 1 | 1 | March 15, 2026 |
| Fire Weather Watch | 1 | 0 | October 14, 2022 |
| Extreme Cold Watch | 1 | 0 | December 23, 2022 |
| Extreme Cold Warning | 1 | 1 | January 26, 2026 |
Tornado history in Jefferson County
32 tornadoes have been recorded in Jefferson County since 1950, killing 4 people and injuring 99. That ranks 47 of 102 counties in Illinois. The most recent was on March 14, 2024 (rated EF1).
Strongest tornadoes in Jefferson County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| December 18, 1957 | F4 | Jefferson County | 16.8 mi | 250 yd | 1 | 45 |
| April 21, 2002 | F3 | Jefferson County | 31.5 mi | 500 yd | 1 | 42 |
| April 19, 1996 | F3 | Jefferson County | 17 mi | 400 yd | 0 | 0 |
| March 23, 2012 | EF2 | Jefferson County | 2.6 mi | 100 yd | 1 | 2 |
| March 30, 1982 | F2 | Jefferson County | 0.8 mi | 100 yd | 1 | 3 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| March 14, 2024 | EF1 | Jefferson County | 0.5 mi | 150 yd | 0 | 0 |
| March 19, 2020 | EF1 | Jefferson County | 2.9 mi | 300 yd | 0 | 0 |
| August 2, 2017 | EF0 | Jefferson County | 0.5 mi | 40 yd | 0 | 0 |
| October 13, 2014 | EF1 | Jefferson County | 0.7 mi | 50 yd | 0 | 0 |
| October 13, 2014 | EF1 | Jefferson County | 3.5 mi | 100 yd | 0 | 0 |
About Jefferson County
- Population: 36,107 (2024 estimate)
- State: Illinois
- NOAA Weather Radio SAME code: 017081 (how to use it)