Iowa planting zones & frost dates
The 6 Iowa cities on this site fall in zones 5a, 5b. Last spring frost dates range from Apr 24 in Des Moines to May 4 in Sioux City.
| City | Zone | Last frost | First frost | Population |
|---|---|---|---|---|
| Des Moines | 5b | Apr 24 | Oct 14 | 213,096 |
| Cedar Rapids | 5a | May 3 | Oct 5 | 137,904 |
| Davenport | 5b | Apr 24 | Oct 17 | 100,938 |
| Sioux City | 5a | May 4 | Oct 1 | 86,875 |
| Ankeny | 5b | Apr 29 | Oct 9 | 76,727 |
| Iowa City | 5b | Apr 28 | Oct 13 | 76,710 |
Frost dates are 30%-risk dates from the nearest suitable NOAA station. Population: Census Vintage 2024 estimates.