Johnson County weather alerts
There are no active weather alerts for Johnson County, IL right now.
Since 2016 the National Weather Service has issued about 806 alerts that included Johnson County, roughly 81 a year. The most common is the severe thunderstorm warning (136 from 2016 to 2025). The last tornado warning was issued on March 16, 2026. 21 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 Johnson County at the moment. This page updates automatically when the National Weather Service issues one. Check neighboring Massac County, Union County, Pope County, Pulaski County.
Johnson County alert history
Alert events that included Johnson County or its forecast zones, from the NWS warning archive.
| Alert type | 2016–2025 | 2026 | Last issued |
|---|---|---|---|
| Severe Thunderstorm Warning | 136 | 13 | August 20, 2026 |
| Dense Fog Advisory | 85 | 3 | October 15, 2026 |
| Flood Watch | 66 | 5 | August 20, 2026 |
| Severe Thunderstorm Watch | 65 | 9 | August 20, 2026 |
| Wind Advisory | 61 | 6 | June 17, 2026 |
| Tornado Watch | 55 | 4 | June 26, 2026 |
| Winter Weather Advisory | 48 | 1 | January 21, 2026 |
| Heat Advisory | 44 | 9 | September 15, 2026 |
| Flood Advisory | 43 | 4 | July 11, 2026 |
| Frost Advisory | 31 | 2 | November 7, 2026 |
| Flash Flood Warning | 27 | 4 | July 11, 2026 |
| Freeze Warning | 26 | 2 | November 8, 2026 |
| Tornado Warning | 25 | 3 | March 16, 2026 |
| Extreme Heat Warning | 13 | 5 | September 1, 2026 |
| Freeze Watch | 13 | 1 | November 8, 2026 |
| Flood Warning | 13 | 2 | July 11, 2026 |
| Cold Weather Advisory | 13 | 2 | January 31, 2026 |
| Winter Storm Watch | 12 | 1 | January 24, 2026 |
| Winter Storm Warning | 10 | 1 | January 24, 2026 |
| Red Flag Warning | 9 | 1 | March 29, 2026 |
| Extreme Heat Watch | 5 | 2 | September 1, 2026 |
| Ice Storm Warning | 2 | 0 | January 5, 2025 |
| Fire Weather Watch | 1 | 0 | October 14, 2022 |
| Extreme Cold Watch | 1 | 0 | December 23, 2022 |
| Extreme Cold Warning | 1 | 1 | January 26, 2026 |
| High Wind Warning | 1 | 1 | March 15, 2026 |
Tornado history in Johnson County
21 tornadoes have been recorded in Johnson County since 1950, killing 1 people and injuring 29. That ranks 68 of 102 counties in Illinois. The most recent was on April 2, 2025 (rated EF2).
Strongest tornadoes in Johnson County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| April 28, 2002 | F3 | Union County | 19.3 mi | 400 yd | 1 | 10 |
| May 26, 2024 | EF3 | Johnson County | 4.9 mi | 300 yd | 0 | 1 |
| April 14, 1972 | F2 | Union County | 30.9 mi | 30 yd | 0 | 9 |
| May 25, 2011 | EF2 | Pulaski County | 19.9 mi | 325 yd | 0 | 0 |
| March 15, 2025 | EF2 | Johnson County | 15.6 mi | 150 yd | 0 | 0 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| April 2, 2025 | EF2 | Johnson County | 6.2 mi | 250 yd | 0 | 0 |
| March 15, 2025 | EF2 | Johnson County | 15.6 mi | 150 yd | 0 | 0 |
| May 26, 2024 | EF1 | Union County | 6.9 mi | 100 yd | 0 | 0 |
| May 26, 2024 | EF3 | Johnson County | 4.9 mi | 300 yd | 0 | 1 |
| June 19, 2015 | EF1 | Johnson County | 0.4 mi | 50 yd | 0 | 0 |
About Johnson County
- Population: 13,320 (2024 estimate)
- State: Illinois
- NOAA Weather Radio SAME code: 017087 (how to use it)