Tiffin
Johnson County4,521 in 2020·7,156 in 2025·+2,635 people
Iowa rankings · Growth
Fastest-growing towns in Iowa
Tiffin has grown fastest of Iowa’s 139 towns of 2,500+: up 58.3% from 4,521 residents in April 2020 to an estimated 7,156 in July 2025 (Census Bureau estimates). The typical town here changed +0.1%; 68 of the 139 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
+58.3%
#2Waukee
Dallas County23,941 in 2020·34,890 in 2025·+10,949 people
#3Bondurant
Polk County7,401 in 2020·9,647 in 2025·+2,246 people
All 139 towns
Growth since 2020, highest first.
139 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 Iowa?
Tiffin (Johnson County): it grew 58.3%, from 4,521 residents in April 2020 to an estimated 7,156 in July 2025. Waukee (+45.7%) and Bondurant (+30.3%) 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 (139 in Iowa). 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 Iowa page.
Go deeper
All Iowa rankings →More Iowa lists
Every list ranks the same 2,500+ towns, so a town’s rank means the same thing on each.
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