Boone County weather alerts
There are no active weather alerts for Boone County, IL right now.
Since 2016 the National Weather Service has issued about 862 alerts that included Boone County, roughly 86 a year. The most common is the dense fog advisory (106 from 2016 to 2025). The last tornado warning was issued on April 18, 2026. 23 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 Boone County at the moment. This page updates automatically when the National Weather Service issues one. Check neighboring Winnebago County, DeKalb County, Rock County, McHenry County.
Boone County alert history
Alert events that included Boone County or its forecast zones, from the NWS warning archive.
| Alert type | 2016–2025 | 2026 | Last issued |
|---|---|---|---|
| Dense Fog Advisory | 106 | 9 | October 20, 2026 |
| Severe Thunderstorm Warning | 100 | 18 | August 21, 2026 |
| Flood Advisory | 93 | 5 | September 20, 2026 |
| Winter Weather Advisory | 91 | 2 | March 16, 2026 |
| Severe Thunderstorm Watch | 71 | 11 | August 21, 2026 |
| Wind Advisory | 63 | 5 | June 17, 2026 |
| Flood Watch | 45 | 7 | September 19, 2026 |
| Cold Weather Advisory | 36 | 3 | January 26, 2026 |
| Flood Warning | 30 | 3 | April 18, 2026 |
| Frost Advisory | 28 | 3 | May 7, 2026 |
| Freeze Warning | 24 | 2 | October 17, 2026 |
| Flash Flood Warning | 23 | 4 | June 11, 2026 |
| Winter Storm Warning | 23 | 1 | March 16, 2026 |
| Tornado Watch | 21 | 4 | June 11, 2026 |
| Winter Storm Watch | 20 | 1 | March 16, 2026 |
| Heat Advisory | 18 | 6 | September 4, 2026 |
| Tornado Warning | 13 | 2 | April 18, 2026 |
| High Wind Warning | 10 | 1 | March 13, 2026 |
| Freeze Watch | 9 | 2 | October 17, 2026 |
| Red Flag Warning | 7 | 1 | February 18, 2026 |
| Extreme Heat Watch | 5 | 0 | July 23, 2025 |
| Extreme Heat Warning | 5 | 2 | July 27, 2026 |
| High Wind Watch | 5 | 0 | March 15, 2025 |
| Extreme Cold Warning | 5 | 1 | January 23, 2026 |
| Fire Weather Watch | 4 | 1 | February 18, 2026 |
| Ice Storm Warning | 2 | 0 | February 22, 2023 |
| Extreme Cold Watch | 2 | 1 | January 23, 2026 |
| Snow Squall Warning | 2 | 0 | February 19, 2022 |
| Blizzard Warning | 1 | 1 | March 16, 2026 |
Tornado history in Boone County
23 tornadoes have been recorded in Boone County since 1950, killing 28 people and injuring 512. That ranks 64 of 102 counties in Illinois. The most recent was on June 3, 2025 (rated EF0).
Strongest tornadoes in Boone County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| April 21, 1967 | F4 | Boone County | 25.5 mi | 1,200 yd | 24 | 450 |
| April 9, 2015 | EF4 | Lee County | 30.1 mi | 700 yd | 2 | 11 |
| January 7, 2008 | EF3 | Boone County | 13.1 mi | 100 yd | 0 | 5 |
| October 8, 1958 | F2 | Stephenson County | 81 mi | 10 yd | 1 | 0 |
| November 22, 2010 | EF2 | Winnebago County | 18.1 mi | 200 yd | 0 | 6 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| June 3, 2025 | EF0 | Boone County | 0.3 mi | 75 yd | 0 | 0 |
| July 12, 2023 | EF0 | Boone County | 2.5 mi | 175 yd | 0 | 0 |
| March 31, 2023 | EF1 | Ogle County | 27.5 mi | 600 yd | 1 | 40 |
| April 30, 2022 | ? | Boone County | 0.1 mi | 30 yd | 0 | 0 |
| April 30, 2022 | EF0 | Boone County | 0.5 mi | 60 yd | 0 | 0 |
About Boone County
- Population: 53,313 (2024 estimate)
- State: Illinois
- NOAA Weather Radio SAME code: 017007 (how to use it)