Lemont Illinois Climate Data

Monthly Average Climate Data for Lemont Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January16.7 °F31.6 °F2.21 in.
February19.4 °F35.6 °F2.07 in.
March29.0 °F47.3 °F2.48 in.
April39.5 °F60.5 °F4.0 in.
May50.3 °F71.5 °F4.86 in.
June60.4 °F81.1 °F4.58 in.
July64.7 °F85.1 °F4.28 in.
August63.2 °F83.1 °F4.17 in.
September55.6 °F77.1 °F3.31 in.
October43.3 °F63.7 °F3.58 in.
November32.4 °F49.2 °F2.51 in.
December22.4 °F36.9 °F2.24 in.
Annual41.4 °F60.2 °F40.29 in.

Climate Data for Lemont 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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