Mason City Illinois Climate Data

Monthly Average Climate Data for Mason City Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January17.5 °F34.4 °F2.08 in.
February20.9 °F39.1 °F1.72 in.
March30.5 °F51.2 °F2.43 in.
April41.2 °F64.4 °F3.98 in.
May52.8 °F74.6 °F4.51 in.
June62.1 °F83.2 °F4.56 in.
July65.0 °F86.0 °F4.33 in.
August62.8 °F84.7 °F3.47 in.
September54.7 °F79.6 °F3.3 in.
October43.1 °F67.0 °F2.98 in.
November32.1 °F51.7 °F2.77 in.
December23.0 °F39.4 °F2.17 in.
Annual42.1 °F62.9 °F38.3 in.

Climate Data for Mason City 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 6a : -10°F to -5°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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