Round Lake, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates
The population of Round Lake, Illinois is 18,588 as of the 2023 American Community Survey, making it the 133rd-largest city in Illinois. The median household income is $108,965, the median home value is $257,400, and the median age is 36.7.
The population has grown 1.5% since 2010 (18,379 → 18,654).
18,588
Population
3343
People / sq mi
$108,965
Median Income
$257,400
Median Home Value
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Round Lake covers 5.6 sq mi of land at 3343 people per square mile.
About Round Lake, IL
Round Lake is distinguished by its share of foreign-born residents, 11.0% of the population. With 18,588 residents, Round Lake is a city in Illinois.
The typical household earns $108,965 a year, above the US median of $78,538. Poverty runs at 6.0%, below the national 12.4%. Median home value is $257,400, with typical rent around $1,494.
Roughly 40.5% of adults have a bachelor’s, above the national 35.0%. About 15.3% of the workforce is home-based, above the national 14.0%, and the average commute runs about 31 minutes each way.
Round Lake village Population History (2010-2024)
The city of Round Lake village had a population of 18,379 in 2010 and 18,654 in 2024, a 1.5% growth over 14 years. The peak was 18,691 in 2020. Average annual growth rate: 0.11%.
18,654
Population (2024)
18,379
Population (2010)
18,691
Peak (2020)
0.11%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 18,379 |
| 2011 | 18,401 |
| 2012 | 18,452 |
| 2013 | 18,522 |
| 2014 | 18,590 |
| 2015 | 18,528 |
| 2016 | 18,486 |
| 2017 | 18,386 |
| 2018 | 18,214 |
| 2019 | 18,100 |
| 2020 | 18,691 |
| 2021 | 18,634 |
| 2022 | 18,571 |
| 2023 | 18,575 |
| 2024 | 18,654 |
Race & Ethnicity
| White | 51.5% |
| Black or African American | 3.1% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 3.4% |
| Two or More Races | 0.2% |
Economy & Income
$108,965
Median Household Income
$42,300
Per Capita Income
6.0%
Poverty Rate
4.8%
Unemployment Rate
Housing
$257,400
Median Home Value
$1,494
Median Rent
79.4%
Owner-Occupied
Education
87.5%
High School+
40.5%
Bachelor's+
Commute
1.5%
Drive Alone
70.2%
Public Transit
15.3%
Work From Home
31.1 min
Avg Commute
Community Profile
11.0%
Foreign Born
58.9%
Non-English at Home
3.6%
Veterans
11.1%
With Disability
94.9%
Health Insurance
99.3%
Internet Access
Employment by Industry
| Manufacturing | 19.4% |
| Professional, Scientific & Management | 16.0% |
| Finance, Insurance & Real Estate | 13.9% |
| Information | 10.3% |
| Education, Health Care & Social Services | 7.2% |
| Retail Trade | 4.9% |
| Construction | 4.2% |
| Arts, Entertainment & Food Services | 3.1% |
| Public Administration | 1.7% |
| Transportation & Warehousing | 0.9% |
| Agriculture & Mining | 0.6% |
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City rankings
Frequently Asked Questions
Round Lake, Illinois has a population of 18,588 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 133rd-largest city in Illinois.
The median household income in Round Lake, Illinois is $108,965, with 6.0% of residents living below the federal poverty level.
The median home value in Round Lake, Illinois is $257,400, with median monthly rent at $1,494 and a homeownership rate of 79.4%.
The median age in Round Lake, Illinois is 36.7 years. The population is 48.9% male and 51.1% female.
The population has grown 1.5% since 2010 (18,379 → 18,654).
Round Lake village, IL Climate
Round Lake village, IL has an average annual temperature of 8.5°C (47°F) and receives about 897 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
8.5°C
Avg Temp
897
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -7° / 20° | 41 mm |
| February | -4° / 25° | 32 mm |
| March | 2° / 35° | 64 mm |
| April | 8° / 46° | 90 mm |
| May | 14° / 57° | 86 mm |
| June | 19° / 67° | 98 mm |
| July | 22° / 72° | 103 mm |
| August | 21° / 70° | 104 mm |
| September | 17° / 63° | 97 mm |
| October | 11° / 51° | 61 mm |
| November | 3° / 38° | 67 mm |
| December | -4° / 26° | 54 mm |
1970–2000 normals from WorldClim 2.1 (~9 km grid). Precipitation can be less precise near mountains or coastlines, where rainfall varies sharply over short distances.
Best time to visit Round Lake village, IL
The most comfortable months to visit Round Lake village, IL are typically August, July and June, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 28°C high). The coldest is January (near -11°C low). August is usually the wettest month.
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.