Harrisburg Illinois Climate Data

Monthly Average Climate Data for Harrisburg Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January25.0 °F41.4 °F3.82 in.
February27.8 °F46.2 °F3.15 in.
March35.9 °F56.2 °F4.24 in.
April45.7 °F67.9 °F5.0 in.
May56.3 °F76.9 °F5.22 in.
June64.8 °F84.8 °F4.75 in.
July68.1 °F88.1 °F3.88 in.
August65.8 °F87.3 °F2.92 in.
September58.0 °F82.0 °F3.15 in.
October46.2 °F70.2 °F3.42 in.
November36.0 °F56.4 °F4.12 in.
December28.3 °F45.5 °F3.75 in.
Annual46.5 °F66.9 °F47.42 in.

Climate Data for Harrisburg Illinois

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateApr. 11 - Apr. 20
Average Days With Frost75-100 Days
Plant Hardiness Zone - 2023Zone 7a : 0°F to 5°F
Plant Hardiness Zone - 2012Zone 6b : -5°F to 0°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationCfa - Humid Subtropical Climate
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