Carroll County Climate
Carroll County, Illinois
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
48.5°F
Annual Precip
38.9"
Annual Snowfall
33.4"
Extreme Heat Days
19
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
5a
Minimum winter temperature range for plant survival
2,917
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Carroll County
Climate Verdict
Carroll County has a cool, averaging 48.5°F annually, moderate rainfall of 38.9 inches per year, rare extreme heat with only 19.1 days above 90°F annually, moderate snowfall of 33.4 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 20.8°F. summers are warm — July averages 72.6°F. Residents experience a substantial 52°F difference between winter and summer.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Carroll County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Carroll County is 4.3°F cooler than the Illinois statewide average of 52.8°F, it is somewhat drier than average for Illinois.
Climate Profile
About Carroll County Weather
One of the Nation's Brisk Regions
Carroll County's 48.5°F average temperature is well below the national median. The county features a humid continental climate with 38.9 inches of annual precipitation, slightly drier than many parts of the Midwest.
Illinois' Chilly Northern Border
Ranking as one of the coldest counties in the state, Carroll's 48.5°F average is 4.3 degrees below the Illinois mean. It also records 33.4 inches of snow, which is near the top of the state rankings.
Coldest Among the Regional Group
Carroll is cooler than Bureau County and significantly snowier than the central counties. With 33.4 inches of snow, it faces the most significant winter accumulation of this eight-county group.
Harsh Winters and Brief Summers
The January average is a frigid 20.8°F, and residents manage 33.4 inches of snow. Summers stay cool at 70.9°F on average, though 19 days still climb above 90°F.
Winterize for Severe Cold
Focus on high-grade home insulation and emergency winter vehicle kits to handle the sub-21°F January lows. The 33.4 inches of snow requires professional-grade removal equipment and consistent sidewalk maintenance.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.