Mason County, Illinois · Frost dates
Mason County frost dates.
First-frost, last-frost, and growing-season length for Mason County, Illinois. Sourced from NOAA 1991-2020 Climate Normals.
Data confidence: high · USDA zone: 6a
32°F — light freeze
Last spring frost
- 10%
- 05-03
- 20%
- 04-26
- 50%
- 04-17
- 80%
- 04-07
- 90%
- 04-02
First fall frost
- 10%
- 10-01
- 20%
- 10-09
- 50%
- 10-19
- 80%
- 10-27
- 90%
- 10-31
28°F — killing freeze
Last spring freeze
- 10%
- 04-21
- 20%
- 04-15
- 50%
- 04-05
- 80%
- 03-28
- 90%
- 03-22
First fall freeze
- 10%
- 10-15
- 20%
- 10-20
- 50%
- 10-29
- 80%
- 11-06
- 90%
- 11-13
Growing season length (days, 28°F threshold)
- Short year
- 177
- Median
- 207
- Long year
- 236
Source NOAA station
HAVANA, IL US
9.2 mi · 30 yrs of record (1991–2020) · 463 ft elev.
Data from HAVANA, IL US, 9.2 miles away with 30-year NOAA record (1991-2020).
Bield Farm earns its predictions.
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