Home   Weather   USA   Decatur   Climate
Flag for USA

Climate & Weather Averages in Decatur, Illinois, USA

Currently: 46 °F. Sunny. (Weather station: Decatur Airport, USA). See more current weather

Annual Weather Averages Near Decatur

Averages are for Decatur Airport, which is 5 miles from Decatur.

Based on weather reports collected during 1985–2015.

All Year Climate & Weather Averages in Decatur

High Temp: 87 °F

Low Temp: 20 °F

Mean Temp: 53 °F

Precipitation: 1.44"

Humidity: 73%

Dew Point: 44 °F

Wind: 9 mph

Pressure: 30.05 "Hg

Visibility: 10 mi

January Climate & Weather Averages in Decatur

High Temp: 36 °F

Low Temp: 20 °F

Mean Temp: 28 °F

Precipitation: 0.81"

Humidity: 80%

Dew Point: 22 °F

Wind: 11 mph

Pressure: 30.13 "Hg

Visibility: 9 mi

February Climate & Weather Averages in Decatur

High Temp: 40 °F

Low Temp: 23 °F

Mean Temp: 31 °F

Precipitation: 0.72"

Humidity: 77%

Dew Point: 24 °F

Wind: 11 mph

Pressure: 30.12 "Hg

Visibility: 9 mi

March Climate & Weather Averages in Decatur

High Temp: 53 °F

Low Temp: 32 °F

Mean Temp: 42 °F

Precipitation: 1.14"

Humidity: 71%

Dew Point: 33 °F

Wind: 11 mph

Pressure: 30.08 "Hg

Visibility: 10 mi

April Climate & Weather Averages in Decatur

High Temp: 66 °F

Low Temp: 42 °F

Mean Temp: 54 °F

Precipitation: 1.89"

Humidity: 66%

Dew Point: 41 °F

Wind: 11 mph

Pressure: 29.97 "Hg

Visibility: 11 mi

May Climate & Weather Averages in Decatur

High Temp: 76 °F

Low Temp: 53 °F

Mean Temp: 64 °F

Precipitation: 2.29"

Humidity: 68%

Dew Point: 53 °F

Wind: 9 mph

Pressure: 29.97 "Hg

Visibility: 10 mi

June Climate & Weather Averages in Decatur

High Temp: 84 °F

Low Temp: 62 °F

Mean Temp: 73 °F

Precipitation: 2.24"

Humidity: 70%

Dew Point: 62 °F

Wind: 7 mph

Pressure: 29.96 "Hg

Visibility: 10 mi

July Climate & Weather Averages in Decatur

High Temp: 87 °F

Low Temp: 65 °F

Mean Temp: 76 °F

Precipitation: 1.55"

Humidity: 72%

Dew Point: 66 °F

Wind: 7 mph

Pressure: 29.99 "Hg

Visibility: 10 mi

August Climate & Weather Averages in Decatur

High Temp: 86 °F

Low Temp: 63 °F

Mean Temp: 74 °F

Precipitation: 1.24"

Humidity: 73%

Dew Point: 64 °F

Wind: 6 mph

Pressure: 30.01 "Hg

Visibility: 9 mi

September Climate & Weather Averages in Decatur

High Temp: 80 °F

Low Temp: 55 °F

Mean Temp: 67 °F

Precipitation: 1.29"

Humidity: 69%

Dew Point: 56 °F

Wind: 7 mph

Pressure: 30.04 "Hg

Visibility: 10 mi

October Climate & Weather Averages in Decatur

High Temp: 67 °F

Low Temp: 44 °F

Mean Temp: 55 °F

Precipitation: 1.42"

Humidity: 69%

Dew Point: 44 °F

Wind: 9 mph

Pressure: 30.08 "Hg

Visibility: 11 mi

November Climate & Weather Averages in Decatur

High Temp: 52 °F

Low Temp: 34 °F

Mean Temp: 43 °F

Precipitation: 1.58"

Humidity: 74%

Dew Point: 34 °F

Wind: 10 mph

Pressure: 30.11 "Hg

Visibility: 10 mi

December Climate & Weather Averages in Decatur

High Temp: 40 °F

Low Temp: 25 °F

Mean Temp: 32 °F

Precipitation: 1.14"

Humidity: 81%

Dew Point: 26 °F

Wind: 10 mph

Pressure: 30.12 "Hg

Visibility: 9 mi

Quick Climate Info

Hottest MonthJuly (76 °F avg)
Coldest MonthJanuary (28 °F avg)
Wettest MonthMay (2.29" avg)
Windiest MonthJanuary (11 mph avg)
Annual precip.17.32" (per year)

Weather by CustomWeather, © 2022