Denison Iowa Climate Data

Monthly Average Climate Data for Denison Iowa

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-11.8 °C-1.8 °C18.54 mm
February-9.6 °C0.9 °C24.64 mm
March-3.5 °C8.3 °C46.99 mm
April2.4 °C15.7 °C86.11 mm
May9.3 °C21.7 °C117.86 mm
June15.3 °C27.3 °C124.71 mm
July17.4 °C28.9 °C103.63 mm
August15.7 °C27.8 °C111.51 mm
September10.7 °C24.6 °C82.3 mm
October3.8 °C17.4 °C65.02 mm
November-3.2 °C8.4 °C36.32 mm
December-8.7 °C1.1 °C30.99 mm
Annual3.2 °C15 °C848.62 mm

Climate Data for Denison Iowa

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 11 - Apr. 20
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 5a : -28.9°C to -26.1°C
Plant Hardiness Zone - 2012Zone 5a : -28.9°C to -26.1°C
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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