Iroquois County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 51st-largest in Illinois
The population of Iroquois County, Illinois is 26,746 as of the 2023 American Community Survey, making it the 51st-largest county in Illinois. The median household income is $62,439, the median home value is $125,400, and the median age is 44.4.
The population of Iroquois County has declined 12.2% since 2010 (29,701 → 26,067), a -0.93% annualized rate.
26,746
Population
-0.93%
Annual growth
24
People / sq mi
$62,439
Median Income
$125,400
Median Home Value
Iroquois County covers 1,117 sq mi of land at 23.9 people per square mile.
About Iroquois County, IL
Iroquois County is distinguished by its share of foreign-born residents, 14.1% of the population. Iroquois County is a county in Illinois with a population of 26,746.
Household earnings are middling, with a median of $62,439 — below the US median of $78,538. Poverty runs at 9.2%, below the national 12.4%. Housing is relatively affordable, with a median home value of $125,400, with typical rent around $793.
College attainment is 16.7%, below the national 35.0%. Around 7.2% of workers work from home, below the national 14.0%, and the average commute runs about 24 minutes each way.
Iroquois County Population History (2010-2024)
The county of Iroquois County had a population of 29,701 in 2010 and 26,067 in 2024, a -12.2% growth over 14 years. The peak was 29,701 in 2010. Average annual growth rate: -0.93%.
26,067
Population (2024)
29,701
Population (2010)
29,701
Peak (2010)
-0.93%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 29,701 |
| 2011 | 29,501 |
| 2012 | 29,270 |
| 2013 | 28,943 |
| 2014 | 28,725 |
| 2015 | 28,529 |
| 2016 | 28,150 |
| 2017 | 27,780 |
| 2018 | 27,450 |
| 2019 | 27,093 |
| 2020 | 26,966 |
| 2021 | 26,761 |
| 2022 | 26,417 |
| 2023 | 26,033 |
| 2024 | 26,067 |
Race & Ethnicity
| White | 89.6% |
| Black or African American | 0.7% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.1% |
| Two or More Races | 0.0% |
Age & Sex
44.4
Median Age
50.6%
Female
49.4%
Male
22.2%
Age 65+
Age Distribution
Children (under 15): 17.4% · Seniors (65+): 22.2%
Income & Poverty
| Median household income | $62,439$-19,263 vs state |
| Mean household income | $81,382 |
| Per-capita income | $34,719 |
| Poverty rate | 9.2%+1.0% vs state |
| Unemployment rate | 2.8% |
| Employment-to-population | 56.0% |
Top Industries by Employment
The largest employment sector in Iroquois County is professional & business services, accounting for 23.6% of workers.
How residents commute
0.3%
Drive alone
2.1%
Carpool
81.1%
Public transit
7.2%
Work from home
24.1 min
Avg commute
Housing
$125,400$-125,100 vs state
Median home value
$793
Median rent
78.5%
Homeownership rate
12,818
Total housing units
88.4%
Occupied
11.6%
Vacant
21.5%
Renter-occupied
Social & access
93.7%
With health insurance
91.7%
With broadband internet
14.1%
Foreign-born
7.0%
Veterans (18+)
17.0%
With a disability
94.0%
Speak language other than English at home
Education
89.1%
High School+
16.7%
Bachelor's+
Largest cities in Illinois
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County rankings
Frequently Asked Questions
Iroquois County, Illinois has a population of 26,746 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 51st-largest county in Illinois. Population density is 24 people per square mile.
The population of Iroquois County has declined 12.2% since 2010 (29,701 → 26,067), a -0.93% annualized rate.
The median household income in Iroquois County, Illinois is $62,439, with mean (average) household income of $81,382 and per-capita income of $34,719. 9.2% of residents live below the federal poverty level.
In Iroquois County, the largest racial and ethnic groups are White (89.6%), Hispanic or Latino (1.1%), Black or African American (0.7%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Iroquois County, Illinois is 44.4 years. Residents are 50.6% female and 49.4% male.
The median home value in Iroquois County is $125,400 and median monthly rent is $793. 78.5% of occupied housing units are owner-occupied. The county has 12,818 total housing units, 11.6% of which are vacant.
The largest employment sector in Iroquois County, Illinois is professional, scientific, and management services, employing 23.6% of workers. The unemployment rate is 2.8%.
Chicago is among the largest cities associated with Iroquois County, Illinois, with a population of 2,707,648.
Iroquois County, IL Climate
Iroquois County, IL has an average annual temperature of 10.3°C (51°F) and receives about 955 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
10.3°C
Avg Temp
955
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -5° / 23° | 40 mm |
| February | -2° / 28° | 41 mm |
| March | 4° / 39° | 78 mm |
| April | 10° / 50° | 96 mm |
| May | 16° / 62° | 103 mm |
| June | 22° / 71° | 101 mm |
| July | 23° / 74° | 103 mm |
| August | 22° / 72° | 91 mm |
| September | 19° / 65° | 87 mm |
| October | 12° / 54° | 70 mm |
| November | 5° / 41° | 77 mm |
| December | -2° / 29° | 68 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 Iroquois County, IL
The most comfortable months to visit Iroquois County, IL are typically June, August and September, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 30°C high). The coldest is January (near -10°C low). May is usually the wettest month.
Where to stay near Iroquois County
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.