Denison Iowa Climate Data

Monthly Average Climate Data for Denison Iowa

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January10.7 °F28.8 °F0.73 in.
February14.8 °F33.7 °F0.97 in.
March25.7 °F46.9 °F1.85 in.
April36.3 °F60.3 °F3.39 in.
May48.8 °F71.1 °F4.64 in.
June59.5 °F81.1 °F4.91 in.
July63.3 °F84.1 °F4.08 in.
August60.3 °F82.1 °F4.39 in.
September51.2 °F76.2 °F3.24 in.
October38.9 °F63.3 °F2.56 in.
November26.2 °F47.1 °F1.43 in.
December16.4 °F34.0 °F1.22 in.
Annual37.7 °F59.1 °F33.41 in.

Climate Data for Denison Iowa

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5a : -20°F to -15°F
Plant Hardiness Zone - 2012Zone 5a : -20°F to -15°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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