Mount Vernon Illinois Climate Data

Monthly Average Climate Data for Mount Vernon Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January22.7 °F39.3 °F2.93 in.
February25.7 °F44.2 °F2.74 in.
March34.3 °F54.4 °F3.8 in.
April44.6 °F65.9 °F4.97 in.
May55.3 °F75.0 °F5.14 in.
June64.0 °F84.0 °F4.65 in.
July67.4 °F87.1 °F4.31 in.
August65.0 °F86.3 °F3.37 in.
September56.8 °F80.2 °F3.28 in.
October45.2 °F68.6 °F3.35 in.
November35.1 °F54.6 °F3.99 in.
December26.9 °F43.4 °F2.96 in.
Annual45.3 °F65.3 °F45.49 in.

Climate Data for Mount Vernon Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 21 - Apr. 30
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 6b : -5°F to 0°F
Plant Hardiness Zone - 2012Zone 6a : -10°F to -5°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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