Union County weather alerts
There are no active weather alerts for Union County, SD right now.
Since 2016 the National Weather Service has issued about 1,014 alerts that included Union County, roughly 101 a year. The most common is the severe thunderstorm warning (154 from 2016 to 2025). The last tornado warning was issued on June 1, 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 Union County at the moment. This page updates automatically when the National Weather Service issues one. Check neighboring Woodbury County, Plymouth County, Clay County, Lincoln County.
Union County alert history
Alert events that included Union County or its forecast zones, from the NWS warning archive.
| Alert type | 2016–2025 | 2026 | Last issued |
|---|---|---|---|
| Severe Thunderstorm Warning | 154 | 26 | October 9, 2026 |
| Flood Warning | 116 | 0 | June 24, 2024 |
| Dense Fog Advisory | 99 | 7 | September 30, 2026 |
| Wind Advisory | 94 | 3 | June 17, 2026 |
| Winter Weather Advisory | 91 | 4 | March 6, 2026 |
| Severe Thunderstorm Watch | 81 | 14 | September 2, 2026 |
| Heat Advisory | 54 | 7 | September 4, 2026 |
| Red Flag Warning | 51 | 10 | May 14, 2026 |
| Cold Weather Advisory | 36 | 3 | March 16, 2026 |
| Winter Storm Watch | 31 | 1 | March 15, 2026 |
| Fire Weather Watch | 30 | 5 | April 16, 2026 |
| Flash Flood Warning | 29 | 4 | October 9, 2026 |
| Flood Watch | 17 | 1 | September 6, 2026 |
| High Wind Warning | 16 | 3 | March 15, 2026 |
| Winter Storm Warning | 16 | 0 | November 28, 2025 |
| Tornado Watch | 15 | 2 | June 10, 2026 |
| Blizzard Warning | 13 | 1 | March 15, 2026 |
| Extreme Heat Warning | 13 | 3 | July 25, 2026 |
| Frost Advisory | 13 | 3 | May 20, 2026 |
| Freeze Warning | 11 | 2 | October 17, 2026 |
| Extreme Heat Watch | 8 | 0 | July 27, 2025 |
| Extreme Cold Warning | 8 | 1 | January 23, 2026 |
| Tornado Warning | 6 | 1 | June 1, 2026 |
| High Wind Watch | 4 | 1 | March 13, 2026 |
| Extreme Cold Watch | 4 | 1 | January 23, 2026 |
| Freeze Watch | 3 | 1 | October 17, 2026 |
| Ice Storm Warning | 1 | 0 | January 2, 2023 |
Tornado history in Union County
21 tornadoes have been recorded in Union County since 1950, injuring 1 people. That ranks 50 of 66 counties in South Dakota. The most recent was on May 11, 2014 (rated EF0).
Strongest tornadoes in Union County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| June 7, 1965 | F3 | Union County | 0.1 mi | 10 yd | 0 | 0 |
| August 12, 1985 | F1 | Clay County | 20 mi | 30 yd | 0 | 0 |
| June 16, 1990 | F1 | Clay County | 9 mi | 60 yd | 0 | 0 |
| July 22, 1983 | F1 | Union County | 0.2 mi | 10 yd | 0 | 0 |
| May 27, 1954 | F1 | Union County | 0.1 mi | 10 yd | 0 | 0 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| May 11, 2014 | EF0 | Union County | 2.4 mi | 50 yd | 0 | 0 |
| June 4, 2005 | F0 | Union County | 0.1 mi | 50 yd | 0 | 0 |
| May 28, 2004 | F0 | Union County | 0.1 mi | 50 yd | 0 | 0 |
| May 28, 2004 | F0 | Union County | 0.1 mi | 50 yd | 0 | 0 |
| April 18, 2004 | F0 | Union County | 4 mi | 100 yd | 0 | 0 |
About Union County
- Population: 17,402 (2024 estimate)
- State: South Dakota
- NOAA Weather Radio SAME code: 046127 (how to use it)