Des Moines, Iowa: freeze dates & growing season

Three different things get called “Des Moines” here, so this page is explicit about all three: the metro label (Des Moines), the anchor geography (Census ZCTA 50309, a downtown ZIP-code area), and the climate record (the NOAA station below). Windows are calculated from the station — not from your street address.

Climate basis: NOAA station Des Moines INTL AP, IA (USW00014933), 4 mi (6 km) from the ZCTA 50309 centroid, elevation 957 ft, on the 1991–2020 climate normals.
Last spring freezeApril 181-in-10 after May 2
First fall freezeOctober 201-in-10 before Oct 4
Frost-free season184 daysmedian at 32°F
Hard freeze, 28°Apr 8Oct 30kills even hardy greens
USDA zone5b-15 to -10°F winter low not frost timing

The year

  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to May 2
The Des Moines year: hatched areas are the freeze-likely seasons in 1991–2020 normals.
What that means in practice
All 79 crops in Des Moines

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

Check a specific ZIP instead

Metro climates vary — elevation, water, and urban heat shift freeze dates by days to weeks. Look up your exact ZIP:

Nearby reviewed metros

Omaha, NE · Kansas City, MO · Sioux Falls, SD · Minneapolis, MN · Madison, WI