Wonder Lake
McHenry County4,012 in 2020·5,593 in 2025·+1,581 people
Illinois rankings · Growth
Fastest-growing towns in Illinois
Wonder Lake has grown fastest of Illinois’ 764 towns of 2,500+: up 39.4% from 4,012 residents in April 2020 to an estimated 5,593 in July 2025 (Census Bureau estimates). The typical town here changed −1.4%; 548 of the 764 lost residents.
Census Bureau population estimates, Vintage 2025: July 1, 2025 against the April 2020 base, both on January 2025 town lines (people a town annexed are in its base, not its growth). Estimates, not counts. Unincorporated communities (census-designated places) get no estimate, so they aren’t listed. A described list: no letters. How grades work
+39.4%
#2Yorkville
Kendall County21,619 in 2020·26,730 in 2025·+5,111 people
#3Pingree Grove
Kane County10,356 in 2020·12,545 in 2025·+2,189 people
All 764 towns
Growth since 2020, highest first. Towns with the same figure share a rank (T = tied; 13 towns here).
764 towns ranked. Not here? See why a town may be missing.
#TownGrowth since 2020People addedResidents
Quick answers
Questions people ask
What is the fastest-growing town in Illinois?
Wonder Lake (McHenry County): it grew 39.4%, from 4,012 residents in April 2020 to an estimated 5,593 in July 2025. Yorkville (+23.6%) and Pingree Grove (+21.1%) follow.
How are these towns ranked?
By the percent change in residents from the Census Bureau’s April 2020 estimates base to its latest July 1 estimate, highest first, on the exact change: two towns shown with the same tenth of a percent keep the order of their unrounded figures, and only an identical change shares a rank (T). The base is the 2020 Census count redrawn on today’s town lines, so a town that annexed land since 2020 changes only by births, deaths and moves, not by the people it took in. How grades work.
Why isn’t my town on this list?
The list covers the towns TownRatings grades that had 2,500+ residents in the 2020 estimates base (764 in Illinois). Census-designated places (unincorporated communities) have no Census Bureau estimates, so they never appear; a town incorporated since 2020, or one TownRatings merges with its twin township, isn’t listed either. Every town is on the Illinois page.
Go deeper
All Illinois rankings →More Illinois lists
Every list ranks the same 2,500+ towns, so a town’s rank means the same thing on each.
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