What is the largest city in Lake County, IL?

Waukegan is the largest city or town in Lake County, with about 89,076 residents.

How many ZIP codes are in Lake County?

Lake County includes 28 ZIP Code Tabulation Areas, including 60002, 60010, 60015, 60020, 60030.

What is the population of Lake County, IL?

About 714,223 people live in Lake County, based on American Community Survey 5-year estimates.

What counties border Lake County?

Lake County borders Cook County, McHenry County, Kenosha County, WI.

Lake County, IL: Cities, ZIP Codes & Local Data

Population

714,223

Land area

444sq mi

People per sq mi

1,610

ZIP codes

28

Lake County at a glance

Lake County is about 7 times as dense as Illinois as a whole.
By population, it ranks 3rd among 102 counties in Illinois.
The median household income is $110,416, 32% above the Illinois median of $83,390.
A typical owner-occupied home is valued at $345,700 (31% above Illinois) and median rent is $1,477 a month.
Its largest cities are Waukegan (89,076), Buffalo Grove (42,891) and Mundelein (31,915).

Local data for Lake County, IL

Counts from official public data

Housing and community stats

Lake County, IL, American Community Survey 2020-2024

Full profile

Median household income

$110,416

Poverty rate

8.3%

Median home value

$345,700

Prices +6.7% in a year

Median rent

$1,477/mo

Homeownership

74.8%

Bachelor's or higher

47.7%

Median age

39.1

Average commute

28.5 min

Largest reported origins and ancestries: Mexican Americans (136,544), German Americans (112,961), Irish Americans (71,697).

Home values and rents Income, education and commute

Economy and federal money

Jobs, income, federal spending and pandemic loans

Details

Unemployment rate

3.6%

Sep 2026, -0.8 pts in a year

Average annual pay

$92,733

325,826 jobs, 2025

Income per person

$103,546

BEA, 2024

Federal spending

$5B

FY 2026, $7,004 per person

PPP loans

$2.1B

25,657 loans, 228,594 jobs reported

Campaign donations

$84.7M

Itemized, 2026 cycle

Economy Federal spending PPP loans

How people get to work

Lake County, IL, workers 16 and older. American Community Survey 5-year estimates

Drove alone65.7%
Carpooled8.5%
Public transit2.7%
Walked2.1%
Bicycle0.1%
Taxi, ride-hailing, motorcycle or other1.4%
Worked from home19.5%

Average one-way commute: 28.5 minutes for people who do not work from home.

Environment and hazard risk

Lake County, IL, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively High

Top: cold wave

Storm events since 1996

815

Most often thunderstorm wind

Flood insurance policies

1,857

0.8% of homes, county

July high / Jan low

82° / 14°F

38.4 inches of rain a year

Hazards, floods and storm history Check a flood zone 70 historic places

Health statistics

Share of adults in Lake County, IL, CDC PLACES estimates

All 40 measures

Obesity

32.9%

U.S. 33.3% about the same

Diabetes

11.2%

U.S. 12.1% -0.9 pts

Smoking

10.4%

U.S. 12.8% -2.4 pts

Uninsured (18-64)

9.2%

U.S. 11.1% -1.9 pts

Cities, towns and ZIP codes in Lake County

Population shown

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Frequently asked questions

What is the largest city in Lake County, IL?: Waukegan is the largest city or town in Lake County, with about 89,076 residents.
How many ZIP codes are in Lake County?: Lake County includes 28 ZIP Code Tabulation Areas, including 60002, 60010, 60015, 60020, 60030.
What is the population of Lake County, IL?: About 714,223 people live in Lake County, based on American Community Survey 5-year estimates.
What counties border Lake County?: Lake County borders Cook County, McHenry County, Kenosha County, WI.