Cook County, Illinois · Frost dates
Cook County frost dates.
First-frost, last-frost, and growing-season length for Cook County, Illinois. Sourced from NOAA 1991-2020 Climate Normals.
Data confidence: high · USDA zone: 6a
32°F — light freeze
Last spring frost
- 10%
- 04-25
- 20%
- 04-20
- 50%
- 04-10
- 80%
- 04-03
- 90%
- 03-29
First fall frost
- 10%
- 10-24
- 20%
- 10-28
- 50%
- 11-05
- 80%
- 11-14
- 90%
- 11-20
28°F — killing freeze
Last spring freeze
- 10%
- 04-14
- 20%
- 04-09
- 50%
- 04-01
- 80%
- 03-22
- 90%
- 03-16
First fall freeze
- 10%
- 11-02
- 20%
- 11-06
- 50%
- 11-15
- 80%
- 11-25
- 90%
- 12-01
Growing season length (days, 28°F threshold)
- Short year
- 202
- Median
- 228
- Long year
- 260
Source NOAA station
CHICAGO NORTHERLY IS, IL US
3.2 mi · 30 yrs of record (1991–2020) · 583 ft elev.
Data from CHICAGO NORTHERLY IS, IL US, 3.2 miles away with 30-year NOAA record (1991-2020).
Bield Farm earns its predictions.
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