Charleston Illinois Climate Data

Monthly Average Climate Data for Charleston Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January20.2 °F35.9 °F2.74 in.
February23.2 °F40.5 °F2.33 in.
March32.2 °F51.8 °F3.03 in.
April43.0 °F64.7 °F4.87 in.
May54.2 °F74.7 °F4.44 in.
June63.0 °F83.1 °F4.86 in.
July65.8 °F86.3 °F4.22 in.
August63.8 °F85.0 °F2.85 in.
September56.0 °F79.6 °F3.06 in.
October44.7 °F67.2 °F3.62 in.
November34.1 °F52.7 °F3.73 in.
December25.6 °F40.7 °F2.85 in.
Annual43.8 °F63.5 °F42.6 in.

Climate Data for Charleston Illinois

Average First Frost DateOct. 11 - Oct. 20
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 6a : -10°F to -5°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation