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Lake County Climate

JanFebMarAprMayJunJulAugSepOctNovDec48.4°AVG °F

Avg Annual Temp

48.4°F

Annual Precip

37.0"

Annual Snowfall

43.3"

Extreme Heat Days

10

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.9"
1.8"
2.4"
3.9"
4.3"
4.3"
3.8"
3.6"
3.4"
3.2"
2.4"
2.0"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

6a

Minimum winter temperature range for plant survival

Growing Degree Days

2,790

Supports most vegetables & fruits

Last spring frost (32°F): 04/29
First fall frost (32°F): 10/21

Seasonal Overview

Comfort ZoneSpring35°58°10.6"Summer67°72°11.7"Fall39°64°9.0"Winter22°28°5.7"20°40°60°80°100°

National Comparison

Warmer than 25% of US counties
Wetter than 38% of US counties
More seasonal variation than 82% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Lake County

Climate Verdict

Lake County has a cool, averaging 48.4°F annually, moderate rainfall of 37.0 inches per year, rare extreme heat with only 10.379999999999999 days above 90°F annually, moderate snowfall of 43.3 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 22.3°F. summers are warm — July averages 72.4°F. Residents experience a substantial 50°F difference between winter and summer.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Lake County is 4.5°F cooler than the Illinois statewide average of 52.8°F, it is somewhat drier than average for Illinois, the county experiences 16.8810321969697 fewer extreme heat days than the state average.

Climate Profile

About Lake County Weather

A cool, lake-influenced climate

Lake County’s 48.4°F annual average is significantly cooler than the national median. Proximity to Lake Michigan creates a unique local climate with increased snowfall and moderated summer heat.

Cooler and snowier than average

The county's 48.4°F average temperature is over four degrees cooler than the Illinois average. It stands out state-wide for its 43.3 inches of snow, far exceeding typical Illinois levels.

The snow leader of the region

Lake County receives 43.3 inches of snow, much more than Kane’s 32.8 inches or Kankakee’s 23.9 inches. It is also slightly cooler than Kane County by about one degree annually.

Mild summers and snowy winters

Summers are very comfortable with only 10 days over 90°F. Winters are the main event, bringing 43.3 inches of snow and an average temperature of 25.3°F.

Invest in heavy snow gear

Residents must prioritize snow removal equipment to handle the massive 43.3 inches of annual accumulation. Summer cooling needs are lower here than in most of Illinois, with only 10 extreme heat days.

Frequently Asked Questions

What is the average temperature in Lake County?
The average annual temperature in Lake County, IL is 48.4°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Lake County get?
Lake County receives an average of 37.0 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 Lake County?
Yes, Lake County receives an average of 43.3 inches of snowfall per year according to NOAA climate normals.
How hot does Lake County get in summer?
The average summer temperature (June-August) in Lake County is 70.3°F. The county experiences an average of 10 days per year above 90°F.
How cold are winters in Lake County?
The average winter temperature (December-February) in Lake County is 25.3°F. January, typically the coldest month, averages 22.3°F.

Track your own weather in Lake 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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