Union County, South Dakota · Frost dates
Union County frost dates.
First-frost, last-frost, and growing-season length for Union County, South Dakota. Sourced from NOAA 1991-2020 Climate Normals.
Data confidence: high · USDA zone: 4b
32°F — light freeze
Last spring frost
- 10%
- 05-16
- 20%
- 05-12
- 50%
- 05-03
- 80%
- 04-25
- 90%
- 04-20
First fall frost
- 10%
- 09-20
- 20%
- 09-24
- 50%
- 10-03
- 80%
- 10-13
- 90%
- 10-17
28°F — killing freeze
Last spring freeze
- 10%
- 05-09
- 20%
- 05-03
- 50%
- 04-24
- 80%
- 04-15
- 90%
- 04-10
First fall freeze
- 10%
- 09-29
- 20%
- 10-03
- 50%
- 10-15
- 80%
- 10-23
- 90%
- 10-27
Growing season length (days, 28°F threshold)
- Short year
- 143
- Median
- 174
- Long year
- 200
Source NOAA station
VERMILLION 2 SE, SD US
14.4 mi · 30 yrs of record (1991–2020) · 1137 ft elev.
Data from VERMILLION 2 SE, SD US, 14.4 miles away with 30-year NOAA record (1991-2020).
Bield Farm earns its predictions.
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