Annual Weather Averages Near City of Johnston
Averages are for Des Moines International Airport, which is 11 miles from City of Johnston.
Based on weather reports collected during 1992–2021.
All Year Climate & Weather Averages in City of Johnston
High Temp: 86 °F
Low Temp: 15 °F
Mean Temp: 51 °F
Precipitation: 2.98"
Humidity: 68%
Dew Point: 40 °F
Wind: 15 mph
Pressure: 30.03 "Hg
Visibility: 9 mi
January Climate & Weather Averages in City of Johnston
High Temp: 31 °F
Low Temp: 15 °F
Mean Temp: 23 °F
Precipitation: 1.01"
Humidity: 74%
Dew Point: 16 °F
Wind: 16 mph
Pressure: 30.14 "Hg
Visibility: 8 mi
February Climate & Weather Averages in City of Johnston
High Temp: 35 °F
Low Temp: 19 °F
Mean Temp: 27 °F
Precipitation: 1.24"
Humidity: 71%
Dew Point: 19 °F
Wind: 16 mph
Pressure: 30.13 "Hg
Visibility: 8 mi
March Climate & Weather Averages in City of Johnston
High Temp: 49 °F
Low Temp: 30 °F
Mean Temp: 40 °F
Precipitation: 2.01"
Humidity: 65%
Dew Point: 28 °F
Wind: 17 mph
Pressure: 30.09 "Hg
Visibility: 9 mi
April Climate & Weather Averages in City of Johnston
High Temp: 62 °F
Low Temp: 41 °F
Mean Temp: 51 °F
Precipitation: 3.80"
Humidity: 60%
Dew Point: 37 °F
Wind: 18 mph
Pressure: 29.98 "Hg
Visibility: 9 mi
May Climate & Weather Averages in City of Johnston
High Temp: 72 °F
Low Temp: 52 °F
Mean Temp: 62 °F
Precipitation: 5.10"
Humidity: 64%
Dew Point: 49 °F
Wind: 16 mph
Pressure: 29.95 "Hg
Visibility: 9 mi
June Climate & Weather Averages in City of Johnston
High Temp: 82 °F
Low Temp: 63 °F
Mean Temp: 73 °F
Precipitation: 5.26"
Humidity: 66%
Dew Point: 60 °F
Wind: 14 mph
Pressure: 29.90 "Hg
Visibility: 9 mi
July Climate & Weather Averages in City of Johnston
High Temp: 86 °F
Low Temp: 67 °F
Mean Temp: 76 °F
Precipitation: 4.00"
Humidity: 69%
Dew Point: 65 °F
Wind: 12 mph
Pressure: 29.95 "Hg
Visibility: 10 mi
August Climate & Weather Averages in City of Johnston
High Temp: 84 °F
Low Temp: 65 °F
Mean Temp: 74 °F
Precipitation: 4.12"
Humidity: 70%
Dew Point: 64 °F
Wind: 12 mph
Pressure: 29.98 "Hg
Visibility: 9 mi
September Climate & Weather Averages in City of Johnston
High Temp: 77 °F
Low Temp: 56 °F
Mean Temp: 67 °F
Precipitation: 3.21"
Humidity: 66%
Dew Point: 55 °F
Wind: 14 mph
Pressure: 30.01 "Hg
Visibility: 10 mi
October Climate & Weather Averages in City of Johnston
High Temp: 64 °F
Low Temp: 43 °F
Mean Temp: 54 °F
Precipitation: 2.77"
Humidity: 65%
Dew Point: 41 °F
Wind: 15 mph
Pressure: 30.04 "Hg
Visibility: 10 mi
November Climate & Weather Averages in City of Johnston
High Temp: 49 °F
Low Temp: 31 °F
Mean Temp: 40 °F
Precipitation: 1.85"
Humidity: 68%
Dew Point: 29 °F
Wind: 17 mph
Pressure: 30.09 "Hg
Visibility: 9 mi
December Climate & Weather Averages in City of Johnston
High Temp: 37 °F
Low Temp: 20 °F
Mean Temp: 28 °F
Precipitation: 1.43"
Humidity: 74%
Dew Point: 21 °F
Wind: 16 mph
Pressure: 30.10 "Hg
Visibility: 8 mi