Ask almost anyone — in Chicago or out of it — and they’ll tell you people are fleeing Illinois. That was true. It stopped being true three years ago, and the Census Bureau’s current estimates say so: Illinois has now gained population three years running — up 23,812 in 2023, 69,644 in 2024, and 16,108 in 2025. We pulled the Bureau’s current estimates and its superseded ones, computed the changes ourselves, and the two sets side by side explain a lot about why the old story still circulates.
Chart: KCM Desk computation from Census Bureau Vintage 2025 state population estimates (NST-EST2025). Hover any bar for the figure.
Why you never heard the story change
Because when the headlines were written, the numbers said something else. In December 2023, the Census Bureau’s estimate for that year was a loss of 32,826 people — and Illinois-is-shrinking stories were written accordingly. The Bureau then revised its methodology for counting international migration, and the current vintage puts that same year at a gain of 23,812. A 57,000-person swing on a single year, arriving in a later data release — long after the original figure had made its headlines. Both numbers came from the same agency; only one of them is current.
What’s actually happening: two flows, not one
The honest version of the story has two moving parts. Illinois still loses people to other states, every single year — that part of the reputation is earned. But the size of that outflow has shrunk dramatically: from about 150,000 net domestic departures in 2022 to about 40,000 in 2025. Meanwhile international migration surged — +94,146 in 2023 and +111,121 in 2024 before falling by more than half to +44,752 in 2025 — and births have exceeded deaths every year. Add the flows together and the state has come out ahead three years straight.
That composition is also the caution. 2025’s gain was the smallest of the three, because the international inflow that drives the growth fell sharply — and a growth streak built on immigration is exposed to federal policy in a way homegrown growth isn’t. If the international inflow keeps shrinking faster than the domestic outflow improves, the arithmetic turns negative again — natural increase alone hasn’t been large enough to carry it.
Chicagoland, county by county
All six of the counties this site covers — Cook and the five collar counties — grew from 2023 to 2025. (The broader Census-defined metro area includes several more counties we don’t track here.) Cook County — the one whose losses drove a decade of headlines — bottomed out in 2023 and has added 51,772 people since:
| County | 2020 | 2023 | 2025 | Since 2023 | Since 2020 |
|---|---|---|---|---|---|
| Cook | 5,263,651 | 5,142,853 | 5,194,625 | +51,772 | -69,026 |
| DuPage | 931,473 | 927,400 | 934,298 | +6,898 | +2,825 |
| Lake | 713,377 | 713,653 | 719,339 | +5,686 | +5,962 |
| Will | 696,901 | 703,872 | 712,253 | +8,381 | +15,352 |
| Kane | 516,364 | 518,295 | 525,757 | +7,462 | +9,393 |
| McHenry | 309,977 | 313,421 | 317,751 | +4,330 | +7,774 |
| Six-county total | 8,431,743 | 8,319,494 | 8,404,023 | +84,529 | -27,720 |
Read the right-hand column honestly: five of the six counties now stand above their 2020 count, and Cook does not — it’s still 69,026 below its July 2020 estimate, even after two years of growth. Both facts are true at once, and which one you lead with is the difference between narrative and data. In 2025, Cook’s pattern matched the state’s in miniature: a net 31,144 residents left for elsewhere in the U.S., while 27,590 arrived from abroad and births did the rest.
What this means if you’re deciding on Chicagoland
The practical takeaway isn’t “Illinois is booming” — it’s that the emptying-out story shouldn’t scare you out of a move that otherwise makes sense. The region’s population is growing again, which squares with what we’ve measured elsewhere: construction permits rising, and Chicago absent from the national housing-shortage worst lists — a growing region that still has room is, for a mover, the favorable combination.
What these numbers are, and aren’t
Population estimates are estimates: the Bureau builds them from administrative records and revises every vintage — the revision that turned 2023 from red to black could be revised again, in either direction. The 2030 census will eventually provide an actual count to check the decade’s estimates against. And nothing here says why anyone moved; the components say how many, not what they were thinking. We computed everything below from the Bureau’s published files, and the method is simple enough to check in a spreadsheet.
Sources & data
- U.S. Census Bureau, Vintage 2025 state population estimates (NST-EST2025-ALLDATA) and county estimates (CO-EST2025-ALLDATA) — totals and components of change, retrieved July 17, 2026
- U.S. Census Bureau, Vintage 2023 state estimates — the superseded figures, kept for the comparison above
- Census Bureau population estimates methodology — including the revised treatment of international migration
Computed by KCM Desk from the files above as of July 17, 2026. Estimates are as of July 1 of each year and are revised annually; we’ll update when Vintage 2026 releases in December. Spot an error? Corrections come first.