Seneca Illinois Climate Data

Monthly Average Climate Data for Seneca Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.4 °F31.7 °F1.98 in.
February18.4 °F35.9 °F1.82 in.
March28.0 °F48.0 °F2.45 in.
April38.7 °F61.1 °F3.6 in.
May49.9 °F72.3 °F4.55 in.
June59.8 °F81.4 °F4.62 in.
July63.5 °F84.5 °F3.99 in.
August61.6 °F82.6 °F3.89 in.
September53.7 °F77.2 °F3.38 in.
October42.0 °F64.3 °F3.11 in.
November31.4 °F49.6 °F2.57 in.
December21.4 °F36.8 °F2.09 in.
Annual40.3 °F60.5 °F38.05 in.

Climate Data for Seneca Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°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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