Decorah Iowa Climate Data

Monthly Average Climate Data for Decorah Iowa

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-13.1 °C-3.6 °C25.15 mm
February-11.2 °C-1.1 °C27.69 mm
March-4.6 °C6 °C49.53 mm
April1.8 °C14.4 °C100.58 mm
May8.3 °C20.9 °C121.92 mm
June14.1 °C26.2 °C155.45 mm
July16.1 °C28.1 °C112.52 mm
August14.8 °C26.9 °C110.49 mm
September10.3 °C23.4 °C92.71 mm
October3.4 °C16.2 °C69.09 mm
November-3 °C6.9 °C47.5 mm
December-9.1 °C-0.4 °C34.8 mm
Annual2.3 °C13.7 °C947.43 mm

Climate Data for Decorah Iowa

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 21 - May 31
Average Days With Frost150-180 Days
Plant Hardiness Zone - 2023Zone 5a : -28.9°C to -26.1°C
Plant Hardiness Zone - 2012Zone 4b : -31.7°C to -28.9°C
Current Drought ConditionsNormal
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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