Frost dates in Union County, South Dakota
The average last spring frost in Union County falls Apr 29 to May 3 and the average first fall frost Oct 3 to Oct 7, depending on the ZIP code (50% odds, 32°F, NOAA 1991–2020 normals). USDA hardiness zone 5a. Places: Alcester, Jefferson, North Sioux City, Richland. Pick a ZIP for 10% and 90% odds, soil temperature and the 7-day freeze forecast.
| ZIP | Place | Last spring frost | First fall frost | Zone |
|---|---|---|---|---|
| 57001 | Alcester | May 1 | Oct 4 | 5a |
| 57025 | Richland | May 3 | Oct 3 | 5a |
| 57038 | Jefferson | Apr 29 | Oct 7 | 5a |
| 57049 | North Sioux City | Apr 29 | Oct 7 | 5a |
Nearby counties
Clay County Lincoln County Yankton County Turner County Minnehaha County Bon Homme County
All South Dakota counties · Download South Dakota frost dates (CSV)
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