River Forest Illinois Climate Data

Monthly Average Climate Data for River Forest Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January17.7 °F31.6 °F2.16 in.
February20.4 °F35.3 °F2.09 in.
March29.6 °F46.1 °F2.33 in.
April39.9 °F58.5 °F3.97 in.
May50.8 °F69.7 °F4.67 in.
June61.0 °F79.8 °F4.33 in.
July66.3 °F84.2 °F3.93 in.
August64.9 °F82.3 °F4.06 in.
September57.0 °F75.7 °F3.29 in.
October44.6 °F62.9 °F3.42 in.
November33.3 °F48.9 °F2.57 in.
December23.4 °F37.1 °F2.29 in.
Annual42.4 °F59.3 °F39.11 in.

Climate Data for River Forest Illinois

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateMay 1 - May 10
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 6a : -10°F to -5°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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