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Randolph County Climate

Randolph County, Illinois

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec55.8°AVG °F

Avg Annual Temp

55.8°F

Annual Precip

43.7"

Annual Snowfall

8.9"

Extreme Heat Days

46

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
2.8"
2.5"
3.7"
4.9"
5.3"
4.2"
4.1"
3.2"
3.2"
3.1"
3.9"
2.9"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

7a

Minimum winter temperature range for plant survival

Growing Degree Days

4,087

Excellent for heat-loving crops

Last spring frost (32°F): 04/12
First fall frost (32°F): 10/30

Seasonal Overview

Comfort ZoneSpring45°65°13.9"Summer74°78°11.4"Fall46°69°10.2"Winter32°36°8.1"20°40°60°80°100°

National Comparison

Warmer than 55% of US counties
Wetter than 55% of US counties
More seasonal variation than 66% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Randolph County

Climate Verdict

Randolph County has a mild, with an average annual temperature of 55.8°F, moderately wet with 43.7 inches of annual precipitation, occasional hot days — 46.35 per year above 90°F, light snow averaging 8.9 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 31.6°F. summers are warm — July averages 77.7°F. The 46°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.

Regional Context

Randolph County closely matches the Illinois statewide average temperature of 52.8°F, the county experiences 19.088967803030304 more extreme heat days than the state average.

Climate Profile

About Randolph County Weather

A Mild and Humid Climate

Randolph County averages 55.8°F annually, placing it above the national median for temperature. This temperate climate experiences distinct seasonal shifts but remains warmer than the national average year-round.

Warmer and Drier Than Average

The county's 55.8°F average exceeds the state average of 52.8°F. Precipitation totals 43.7 inches annually, slightly more than the Illinois average of 41.7 inches.

Southern Central Regional Comparison

Randolph is warmer than Richland County and experiences 46 days of extreme heat. This is significantly higher than northern Illinois counties, marking it as a warmer regional hub.

Long Summers and Moderate Winters

Summers are intense with 46 days above 90°F and a July average of 77.7°F. Winters are relatively short, with only 8.9 inches of annual snowfall and a January average of 31.6°F.

Manage the Summer Heat Spike

With over 45 days of extreme heat, reliable air conditioning and cooling centers are essential. Winter preparation is simple, as less than 9 inches of snow falls in a typical year.

Frequently Asked Questions

What is the average temperature in Randolph County?
The average annual temperature in Randolph County, IL is 55.8°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Randolph County get?
Randolph County receives an average of 43.7 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Randolph County?
Yes, Randolph County receives an average of 8.9 inches of snowfall per year according to NOAA climate normals.
How hot does Randolph County get in summer?
The average summer temperature (June-August) in Randolph County is 75.9°F. The county experiences an average of 46 days per year above 90°F.
How cold are winters in Randolph County?
The average winter temperature (December-February) in Randolph County is 34.3°F. January, typically the coldest month, averages 31.6°F.

Track your own weather in Randolph County

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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.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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