Union County weather, town by town
6 places in Union County, South Dakota, each with its own live forecast and radar, and where a station sits close enough, measured weather records.
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Measured at the NOAA stations serving these towns, daily records 1893 to 2026. Station extremes, not official state records.
Union County Weather Facts
Union County has 6 places on myweatherrock (4 cities, 2 census-designated places), each with its own live forecast, hourly timeline, ten day outlook and radar. The hottest day in the station records is 114°F at Vermillion 2 Se on July 17, 1936. The coldest night is -44°F at Centerville 6 Se on January 12, 1912. The wettest day brought 8.92 inches of rain at Newcastle on July 17, 1996. The biggest single-day snow measured 22.01 inches at Centerville 6 Se on February 18, 1962. Those are station measurements from NOAA's daily records, 1893 to 2026, not official state records. By area the largest place is Richland, about 6 square miles.
About Union County weather
The map on the Now tab shows every Union County town's current temperature from our own server, one dot per town. Tap any dot, or type a town above, for that town's full forecast.
What the weather is usually like
Across the 6 Union County towns with station normals, the warmest month is July, when the day usually reaches 86°F, and the coldest is January, when the night usually falls to 10°F. May is the wettest, with rain on about 12 days. July afternoons run from about 84°F in Alcester to 87°F in Elk Point. January nights run from about 7°F in Alcester to 11°F in Dakota Dunes.
Means of the 1991 to 2020 station normals serving these towns, as published by NOAA; each town's page carries its own.
Where these numbers come from
- Current conditions and forecast: NOAA forecast grids decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
- Records: computed by myweatherrock from NOAA GHCN-Daily station records at the stations serving these towns. Measurements, not estimates.
- Warnings and alerts: the National Weather Service, passed through unchanged.
Union County weather records
Measured at the NOAA stations serving these towns, daily records 1893 to 2026. Station extremes, not official state records.
Common questions about Union County weather
- What is the hottest temperature recorded at a Union County station?
- 114°F at Vermillion 2 Se on July 17, 1936, in the NOAA daily station records myweatherrock holds (1893 to 2026).
- What is the coldest temperature recorded at a Union County station?
- -44°F at Centerville 6 Se on January 12, 1912.
- What is the most rain a Union County station has measured in one day?
- 8.92 inches at Newcastle on July 17, 1996.
- What is the biggest one-day snowfall at a Union County station?
- 22.01 inches at Centerville 6 Se on February 18, 1962.
- How many Union County towns have a weather page here?
- 6: 4 cities, 2 census-designated places. Each page carries current conditions, the hourly timeline, the ten day outlook, radar, and where a station sits close enough, measured records.
- Where does the Union County forecast come from?
- NOAA forecast grids (the National Weather Service digital forecast, the National Blend of Models, HRRR and GFS) decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
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