Thornton Illinois Climate Data

Monthly Average Climate Data for Thornton Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January17.3 °F32.1 °F2.21 in.
February20.0 °F35.8 °F2.13 in.
March29.2 °F46.7 °F2.38 in.
April39.4 °F59.3 °F3.91 in.
May50.4 °F70.0 °F4.45 in.
June60.3 °F79.9 °F4.68 in.
July65.1 °F83.9 °F4.35 in.
August63.3 °F82.1 °F4.13 in.
September55.7 °F76.0 °F3.25 in.
October43.7 °F63.3 °F3.48 in.
November33.0 °F49.3 °F2.75 in.
December23.0 °F37.3 °F2.3 in.
Annual41.7 °F59.6 °F40.02 in.

Climate Data for Thornton Illinois

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateApr. 11 - Apr. 20
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 ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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