Annual Weather Averages in Southern Illinois Airport
Southern Illinois Airport is 30 miles from Rend Lake State Wildlife Refuge, so the actual climate in Rend Lake State Wildlife Refuge can vary a bit.
Based on weather reports collected during 1992–2021.
All Year Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 89 °F
Low Temp: 25 °F
Mean Temp: 57 °F
Precipitation: 3.48"
Humidity: 71%
Dew Point: 47 °F
Wind: 11 mph
Pressure: 30.06 "Hg
Visibility: 9 mi
January Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 42 °F
Low Temp: 25 °F
Mean Temp: 34 °F
Precipitation: 2.54"
Humidity: 73%
Dew Point: 26 °F
Wind: 14 mph
Pressure: 30.16 "Hg
Visibility: 9 mi
February Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 47 °F
Low Temp: 29 °F
Mean Temp: 38 °F
Precipitation: 2.49"
Humidity: 70%
Dew Point: 28 °F
Wind: 14 mph
Pressure: 30.13 "Hg
Visibility: 9 mi
March Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 57 °F
Low Temp: 37 °F
Mean Temp: 47 °F
Precipitation: 4.08"
Humidity: 66%
Dew Point: 36 °F
Wind: 14 mph
Pressure: 30.08 "Hg
Visibility: 9 mi
April Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 68 °F
Low Temp: 46 °F
Mean Temp: 57 °F
Precipitation: 4.74"
Humidity: 65%
Dew Point: 45 °F
Wind: 15 mph
Pressure: 29.98 "Hg
Visibility: 10 mi
May Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 77 °F
Low Temp: 56 °F
Mean Temp: 67 °F
Precipitation: 4.26"
Humidity: 71%
Dew Point: 57 °F
Wind: 12 mph
Pressure: 29.98 "Hg
Visibility: 9 mi
June Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 86 °F
Low Temp: 65 °F
Mean Temp: 76 °F
Precipitation: 4.19"
Humidity: 70%
Dew Point: 65 °F
Wind: 10 mph
Pressure: 29.96 "Hg
Visibility: 9 mi
July Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 89 °F
Low Temp: 69 °F
Mean Temp: 79 °F
Precipitation: 3.62"
Humidity: 73%
Dew Point: 69 °F
Wind: 8 mph
Pressure: 29.99 "Hg
Visibility: 9 mi
August Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 87 °F
Low Temp: 66 °F
Mean Temp: 77 °F
Precipitation: 2.72"
Humidity: 74%
Dew Point: 68 °F
Wind: 7 mph
Pressure: 30.01 "Hg
Visibility: 8 mi
September Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 81 °F
Low Temp: 57 °F
Mean Temp: 69 °F
Precipitation: 3.09"
Humidity: 73%
Dew Point: 60 °F
Wind: 7 mph
Pressure: 30.04 "Hg
Visibility: 8 mi
October Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 70 °F
Low Temp: 46 °F
Mean Temp: 58 °F
Precipitation: 3.46"
Humidity: 69%
Dew Point: 48 °F
Wind: 10 mph
Pressure: 30.07 "Hg
Visibility: 9 mi
November Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 57 °F
Low Temp: 36 °F
Mean Temp: 46 °F
Precipitation: 3.51"
Humidity: 70%
Dew Point: 36 °F
Wind: 13 mph
Pressure: 30.14 "Hg
Visibility: 9 mi
December Climate & Weather Averages in Rend Lake State Wildlife Refuge
High Temp: 46 °F
Low Temp: 29 °F
Mean Temp: 37 °F
Precipitation: 3.10"
Humidity: 75%
Dew Point: 30 °F
Wind: 13 mph
Pressure: 30.14 "Hg
Visibility: 9 mi