Jefferson County weather alerts
There are no active weather alerts for Jefferson County, NY right now.
Since 2016 the National Weather Service has issued about 840 alerts that included Jefferson County, roughly 84 a year. The most common is the winter weather advisory (165 from 2016 to 2025). The last tornado warning was issued on May 13, 2026. 5 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 Oswego County, St. Lawrence County, Lewis 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 |
|---|---|---|---|
| Winter Weather Advisory | 165 | 10 | March 17, 2026 |
| Severe Thunderstorm Warning | 156 | 16 | September 3, 2026 |
| Wind Advisory | 75 | 4 | June 18, 2026 |
| Winter Storm Watch | 75 | 3 | March 13, 2026 |
| Lake Effect Snow Warning | 55 | 2 | March 17, 2026 |
| Winter Storm Warning | 44 | 4 | March 13, 2026 |
| Severe Thunderstorm Watch | 31 | 2 | June 30, 2026 |
| Flood Watch | 30 | 3 | August 2, 2026 |
| High Wind Warning | 28 | 2 | June 18, 2026 |
| Flood Warning | 26 | 3 | April 3, 2026 |
| Frost Advisory | 24 | 2 | May 22, 2026 |
| High Wind Watch | 22 | 1 | March 15, 2026 |
| Cold Weather Advisory | 18 | 2 | February 8, 2026 |
| Heat Advisory | 18 | 3 | July 14, 2026 |
| Freeze Warning | 12 | 1 | May 12, 2026 |
| Extreme Cold Warning | 11 | 3 | February 7, 2026 |
| Tornado Warning | 11 | 1 | May 13, 2026 |
| Extreme Cold Watch | 6 | 2 | February 7, 2026 |
| Tornado Watch | 6 | 2 | September 2, 2026 |
| Blizzard Warning | 5 | 0 | December 23, 2022 |
| Flash Flood Warning | 5 | 0 | August 9, 2024 |
| Dense Fog Advisory | 5 | 2 | March 21, 2026 |
| Snow Squall Warning | 5 | 0 | February 3, 2023 |
| Freeze Watch | 4 | 0 | May 18, 2023 |
| Ice Storm Warning | 2 | 0 | March 29, 2025 |
| Extreme Heat Warning | 1 | 0 | July 1, 2018 |
Tornado history in Jefferson County
5 tornadoes have been recorded in Jefferson County since 1950, injuring 1 people. That ranks 41 of 62 counties in New York. The most recent was on September 9, 2024 (rated unknown).
Strongest tornadoes in Jefferson County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| August 28, 1983 | F1 | Jefferson County | 6 mi | 300 yd | 0 | 1 |
| July 1, 1959 | F1 | Jefferson County | 0.1 mi | 150 yd | 0 | 0 |
| August 20, 1993 | F0 | Jefferson County | 0.2 mi | 13 yd | 0 | 0 |
| August 5, 2003 | F0 | Jefferson County | 0.1 mi | 5 yd | 0 | 0 |
| September 9, 2024 | ? | Jefferson County | 0.1 mi | 50 yd | 0 | 0 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| September 9, 2024 | ? | Jefferson County | 0.1 mi | 50 yd | 0 | 0 |
| August 5, 2003 | F0 | Jefferson County | 0.1 mi | 5 yd | 0 | 0 |
| August 20, 1993 | F0 | Jefferson County | 0.2 mi | 13 yd | 0 | 0 |
| August 28, 1983 | F1 | Jefferson County | 6 mi | 300 yd | 0 | 1 |
| July 1, 1959 | F1 | Jefferson County | 0.1 mi | 150 yd | 0 | 0 |
About Jefferson County
- Population: 113,140 (2024 estimate)
- State: New York
- NOAA Weather Radio SAME code: 036045 (how to use it)