Jefferson County, Illinois · Frost dates
Jefferson County frost dates.
First-frost, last-frost, and growing-season length for Jefferson County, Illinois. Sourced from NOAA 1991-2020 Climate Normals.
Data confidence: high · USDA zone: 6a
32°F — light freeze
Last spring frost
- 10%
- 04-26
- 20%
- 04-21
- 50%
- 04-11
- 80%
- 04-02
- 90%
- 03-30
First fall frost
- 10%
- 10-09
- 20%
- 10-14
- 50%
- 10-22
- 80%
- 10-29
- 90%
- 11-01
28°F — killing freeze
Last spring freeze
- 10%
- 04-17
- 20%
- 04-10
- 50%
- 04-01
- 80%
- 03-22
- 90%
- 03-16
First fall freeze
- 10%
- 10-20
- 20%
- 10-24
- 50%
- 11-01
- 80%
- 11-10
- 90%
- 11-16
Growing season length (days, 28°F threshold)
- Short year
- 186
- Median
- 214
- Long year
- 245
Source NOAA station
MT VERNON 3 NE, IL US
5.1 mi · 30 yrs of record (1991–2020) · 490 ft elev.
Data from MT VERNON 3 NE, IL US, 5.1 miles away with 30-year NOAA record (1991-2020).
Bield Farm earns its predictions.
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