Iowa City, IA Frost Dates
The last spring frost in Iowa City usually comes around April 21 and the first fall frost around October 18.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | April 21 | October 18 |
| Hard freeze, 28°F | April 9 | October 28 |
Growing season: about 180 days.
Frequently asked questions
When is the last frost in Iowa City, IA?
The median date of the last spring frost (32°F) is April 21. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past April 21 lowers the risk for tender plants.
When is the first frost in Iowa City?
The median date of the first fall frost (32°F) is October 18, and a hard freeze (28°F) usually follows around October 28.
How long is the growing season in Iowa City?
About 180 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00014937. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.