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Frost dates for Ottumwa, Iowa

In a typical year, Ottumwa’s last spring frost lands around Apr 23 and the first fall frost around Oct 14, a growing season of about 174 days. These are odds drawn from 30-year NOAA climate normals, not a promise. USDA zone 5b.

Right now the typical frost season has arrived; planting waits for spring.

Last spring frost and first fall frost odds for Ottumwa, Iowa
OddsLast spring frostFirst fall frost
10 percentApr 9Sep 29
50 percentApr 23Oct 14
90 percentMay 7Oct 26

A 10 percent year is an early year, a 90 percent year a late one. Frost-sensitive planting usually waits for the 90 percent side of the last-frost band.

Soil in Ottumwa is typically around 51°F at 4 inches this time of year, estimated from the last two weeks of normal air temperatures.

See what is plantable in your ZIP with the what-to-plant lookup.

Common questions

When is the last frost in Ottumwa, Iowa?

Ottumwa’s last spring frost falls around April 23 in a typical year. One year in ten it is done by April 9, and one year in ten frost holds on until May 7. Frost-sensitive planting usually waits for the late side of that band.

When is the first fall frost in Ottumwa?

The first fall frost arrives around October 14 in a typical year, as early as September 29 in an early year and as late as October 26 in a late one.

How long is the growing season in Ottumwa?

About 174 days, counted between the typical last spring frost and the typical first fall frost.

What USDA zone is Ottumwa in?

Ottumwa is in USDA hardiness zone 5b under the 2023 USDA Plant Hardiness Zone Map.

Dates come from 30-year NOAA climate normals for the nearest reporting station. They describe odds, not a forecast.

Nearby cities

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