Jefferson Iowa Climate Data

Monthly Average Climate Data for Jefferson Iowa

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January10.4 °F28.3 °F0.91 in.
February14.7 °F33.1 °F1.19 in.
March25.9 °F46.4 °F1.99 in.
April37.0 °F60.9 °F3.77 in.
May49.4 °F71.5 °F4.94 in.
June59.8 °F80.9 °F5.21 in.
July63.5 °F84.3 °F4.21 in.
August60.8 °F82.2 °F4.01 in.
September51.7 °F76.4 °F3.17 in.
October39.5 °F63.5 °F2.54 in.
November27.1 °F47.0 °F1.78 in.
December16.5 °F33.6 °F1.32 in.
Annual38 °F59 °F35.04 in.

Climate Data for Jefferson Iowa

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 1 - May 10
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5a : -20°F to -15°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
2024 plantmaps.com