Iroquois County Climate
Iroquois County, Illinois
Avg Annual Temp
50.8°F
Annual Precip
39.6"
Annual Snowfall
21.1"
Extreme Heat Days
15.7
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Seasonal Overview
National Comparison
Climate Profile
About Iroquois County Weather
Cooler than average with typical Midwest seasons
The 50.8°F average temperature is over two degrees lower than the national median. The county experiences a moderate precipitation profile of 39.6 inches annually.
Trailing the Illinois state temperature average
Iroquois County stays cooler than the state average of 52.8°F, coming in at 50.8°F. This makes it part of the cooler northern-central Illinois belt.
Drier and cooler than its southern neighbors
With 39.6 inches of rain, it is drier than Jasper County further south. It also sees more snow than southern counties, averaging 21.1 inches a year.
Mild summers with 16 days of heat
Summer heat is relatively rare compared to southern Illinois, with only 16 days above 90°F. Winter brings a cold average of 27.2°F and 21.1 inches of snow.
Balance heating needs with moderate snow prep
Prepare for a long winter season with average January lows of 24.1°F. Maintenance for 21.1 inches of snow is necessary for safe winter travel.
Frequently Asked Questions
What is the average temperature in Iroquois County?
How much rain does Iroquois County get?
Does it snow in Iroquois County?
How hot does Iroquois County get in summer?
How cold are winters in Iroquois County?
Track your own weather in Iroquois County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.