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Whiteside County Climate

Whiteside County, Illinois

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec49.1°AVG °F

Avg Annual Temp

49.1°F

Annual Precip

37.9"

Annual Snowfall

30.0"

Extreme Heat Days

15

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.6"
1.6"
2.6"
3.7"
4.6"
4.9"
4.1"
4.1"
3.6"
2.8"
2.3"
1.9"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5b

Minimum winter temperature range for plant survival

Growing Degree Days

3,060

Supports most vegetables & fruits

Last spring frost (32°F): 04/26
First fall frost (32°F): 10/26

Seasonal Overview

Comfort ZoneSpring37°61°10.9"Summer70°74°13.1"Fall39°64°8.8"Winter21°27°5.1"20°40°60°80°100°

National Comparison

Warmer than 27% of US counties
Wetter than 40% of US counties
More seasonal variation than 88% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Whiteside County

Climate Verdict

Whiteside County has a cool, averaging 49.1°F annually, moderate rainfall of 37.9 inches per year, rare extreme heat with only 15.25 days above 90°F annually, moderate snowfall of 30.0 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 20.9°F. summers are warm — July averages 73.5°F. Residents experience a substantial 53°F difference between winter and summer.

Outdoor & Gardening Guidance

Growing season and gardening data is currently limited for Whiteside County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Whiteside County is 3.7°F cooler than the Illinois statewide average of 52.8°F, it is somewhat drier than average for Illinois.

Climate Profile

About Whiteside County Weather

A true northern continental climate

Whiteside County averages 49.1°F, which is notably cooler than the national median. It is drier than many peers, with 37.9 inches of annual precipitation.

Among the coldest in Illinois

At 49.1°F, Whiteside is much colder than the state average of 52.8°F. It ranks as one of the northernmost and coldest counties in Illinois, with harsh winter conditions.

Highest snowfall in the area

With 30 inches of annual snow, Whiteside is significantly snowier than nearby Will County. It experiences only 15 days of extreme heat, fewer than almost any county to its south.

Harsh winters and mild summers

Winters are intense, with a January average of 20.9°F and substantial snowfall. Summers remain pleasant, averaging 71.8°F with very few days of oppressive heat.

Winter gear is a priority

Heavy-duty snow removal equipment is a must for the 30 inches of annual snowfall. Residents should prioritize home insulation and high-performance heating for the sub-freezing winter months.

Frequently Asked Questions

What is the average temperature in Whiteside County?
The average annual temperature in Whiteside County, IL is 49.1°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Whiteside County get?
Whiteside County receives an average of 37.9 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 Whiteside County?
Yes, Whiteside County receives an average of 30.0 inches of snowfall per year according to NOAA climate normals.
How hot does Whiteside County get in summer?
The average summer temperature (June-August) in Whiteside County is 71.8°F. The county experiences an average of 15 days per year above 90°F.
How cold are winters in Whiteside County?
The average winter temperature (December-February) in Whiteside County is 24.3°F. January, typically the coldest month, averages 20.9°F.

Track your own weather in Whiteside 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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