Jefferson County weather alerts
There are no active weather alerts for Jefferson County, WI right now.
Since 2016 the National Weather Service has issued about 831 alerts that included Jefferson County, roughly 83 a year. The most common is the severe thunderstorm warning (181 from 2016 to 2025). The last tornado warning was issued on July 27, 2026. 50 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 Waukesha County, Rock County, Dodge County, Dane 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 | 181 | 27 | August 18, 2026 |
| Dense Fog Advisory | 115 | 7 | October 20, 2026 |
| Winter Weather Advisory | 107 | 8 | March 16, 2026 |
| Severe Thunderstorm Watch | 64 | 13 | August 21, 2026 |
| Flood Warning | 47 | 8 | April 18, 2026 |
| Wind Advisory | 46 | 4 | May 12, 2026 |
| Cold Weather Advisory | 39 | 3 | January 26, 2026 |
| Frost Advisory | 31 | 6 | May 11, 2026 |
| Flood Watch | 24 | 4 | September 19, 2026 |
| Flood Advisory | 23 | 5 | April 17, 2026 |
| Tornado Warning | 23 | 8 | July 27, 2026 |
| Heat Advisory | 21 | 3 | July 27, 2026 |
| Winter Storm Watch | 18 | 1 | March 15, 2026 |
| Winter Storm Warning | 18 | 1 | March 15, 2026 |
| Tornado Watch | 17 | 4 | June 17, 2026 |
| Freeze Warning | 16 | 2 | October 17, 2026 |
| Flash Flood Warning | 8 | 5 | April 18, 2026 |
| Extreme Heat Warning | 6 | 1 | June 29, 2026 |
| High Wind Warning | 6 | 1 | March 13, 2026 |
| Extreme Heat Watch | 4 | 1 | June 29, 2026 |
| Snow Squall Warning | 4 | 0 | February 19, 2022 |
| Freeze Watch | 3 | 1 | October 17, 2026 |
| Fire Weather Watch | 3 | 0 | April 13, 2023 |
| Red Flag Warning | 3 | 0 | April 13, 2023 |
| High Wind Watch | 2 | 0 | December 16, 2021 |
| Extreme Cold Warning | 2 | 1 | January 23, 2026 |
| Blizzard Warning | 0 | 1 | March 16, 2026 |
| Extreme Cold Watch | 0 | 2 | January 23, 2026 |
Tornado history in Jefferson County
50 tornadoes have been recorded in Jefferson County since 1950, killing 5 people and injuring 65. That ranks 6 of 72 counties in Wisconsin. The most recent was on June 22, 2024 (rated EF1).
Strongest tornadoes in Jefferson County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| August 18, 2005 | F3 | Dane County | 18.6 mi | 600 yd | 1 | 23 |
| June 5, 1980 | F3 | Jefferson County | 10.7 mi | 100 yd | 0 | 0 |
| April 11, 1965 | F2 | Jefferson County | 14.5 mi | 1,320 yd | 3 | 28 |
| March 27, 1991 | F2 | Green County | 32 mi | 440 yd | 1 | 5 |
| June 15, 1981 | F2 | Jefferson County | 28.7 mi | 50 yd | 0 | 3 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| June 22, 2024 | EF1 | Jefferson County | 2.1 mi | 150 yd | 0 | 0 |
| June 22, 2024 | EF1 | Dane County | 4.5 mi | 300 yd | 0 | 0 |
| May 26, 2024 | EF0 | Jefferson County | 5.6 mi | 30 yd | 0 | 0 |
| May 26, 2024 | EF0 | Rock County | 14.4 mi | 50 yd | 0 | 0 |
| February 8, 2024 | EF2 | Rock County | 25.9 mi | 750 yd | 0 | 1 |
About Jefferson County
- Population: 86,245 (2024 estimate)
- State: Wisconsin
- NOAA Weather Radio SAME code: 055055 (how to use it)