weatherbycounty

Jo Daviess County Climate

Jo Daviess County, Illinois

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec47.4°AVG °F

Avg Annual Temp

47.4°F

Annual Precip

39.2"

Annual Snowfall

34.6"

Extreme Heat Days

8

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.3"
1.6"
2.3"
3.9"
4.3"
5.9"
4.7"
4.1"
4.0"
3.1"
2.4"
1.8"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5a

Minimum winter temperature range for plant survival

Growing Degree Days

2,770

Supports most vegetables & fruits

Last spring frost (32°F): 04/27
First fall frost (32°F): 10/09

Seasonal Overview

Comfort ZoneSpring35°59°10.4"Summer69°72°14.7"Fall37°62°9.4"Winter19°25°4.7"20°40°60°80°100°

National Comparison

Warmer than 21% of US counties
Wetter than 44% of US counties
More seasonal variation than 88% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Jo Daviess County

Climate Verdict

Jo Daviess County has a cool, averaging 47.4°F annually, moderate rainfall of 39.2 inches per year, rare extreme heat with only 8.266666666666666 days above 90°F annually, moderate snowfall of 34.6 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 19.2°F. summers are warm — July averages 71.9°F. Residents experience a substantial 53°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

Jo Daviess County is 5.4°F cooler than the Illinois statewide average of 52.8°F, it is somewhat drier than average for Illinois, the county experiences 18.994365530303032 fewer extreme heat days than the state average.

Climate Profile

About Jo Daviess County Weather

A cool northern continental climate

With an average annual temperature of 47.4°F, Jo Daviess is significantly cooler than the national median. This region experiences a true four-season climate defined by brisk air and heavy winter accumulation.

Among the coldest counties in Illinois

The county's 47.4°F average is over five degrees colder than the Illinois state average of 52.8°F. It sits near the bottom of the state temperature rankings, emphasizing its northern latitude.

Coldest in the regional comparison

Jo Daviess is much colder than Kane County, which averages 49.5°F. It also records 34.6 inches of snow, far surpassing the 12.5 inches seen in Jersey County to the south.

Heavy snow and mild summers

Winter is rigorous here, with temperatures averaging just 22.6°F and delivering 34.6 inches of snow. Conversely, summers are comfortable, featuring only 8 days of extreme heat above 90°F.

Prepare for significant winter weather

High-quality snow removal equipment and heavy-duty winter apparel are essential for the 34.6-inch annual snowfall. Homeowners can focus more on heating efficiency than extreme summer cooling.

Frequently Asked Questions

What is the average temperature in Jo Daviess County?
The average annual temperature in Jo Daviess County, IL is 47.4°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Jo Daviess County get?
Jo Daviess County receives an average of 39.2 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 Jo Daviess County?
Yes, Jo Daviess County receives an average of 34.6 inches of snowfall per year according to NOAA climate normals.
How hot does Jo Daviess County get in summer?
The average summer temperature (June-August) in Jo Daviess County is 70.1°F. The county experiences an average of 8 days per year above 90°F.
How cold are winters in Jo Daviess County?
The average winter temperature (December-February) in Jo Daviess County is 22.6°F. January, typically the coldest month, averages 19.2°F.

Track your own weather in Jo Daviess County

Ambient Weather personal weather stations give you hyperlocal climate data.

Shop Weather Stations →

Sponsored

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
← Back to Illinois