Last frost date in Des Moines, IA

Average last frost
April 18

Expect the last frost in Des Moines around April 18. Frost after May 2 happens in only one year out of ten. The first fall frost usually arrives about October 20, which leaves 184 frost-free days. An early freeze before October 4 happens one year in ten.

Safe after (10% risk)
May 2
Average first frost
Oct 20
Frost-free season
184 days
Hard freeze (28°F) ends
Apr 8
Next 7 nights in Des Moines

No frost in the next 7 nights

Later than usual: the average first frost here is October 20.

National Weather Service forecast, updated Oct 22, 12:57 UTC

  1. ThuOct 2254°
  2. FriOct 2358°
  3. SatOct 2456°
  4. SunOct 2553°
  5. MonOct 2647°
  6. TueOct 2744°
  7. WedOct 2846°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 18First frost Oct 20184 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND184 frost-free days
Frost risk through the year at Des Moines International Airport, 3.5 miles from Des Moines.

Planting calendar for Des Moines

Windows count forward or back from the average frost dates above. Click a crop for dates across Iowa.

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 25–May 9
PumpkinsMay 2–May 16
SunflowersApr 18–May 9
CucumbersMay 2–May 9
CornApr 25–May 9
Sweet potatoesMay 9–May 23
WatermelonMay 2–May 16
Green beansApr 25–May 16
ZucchiniApr 25–May 9
OkraMay 9–May 23
PeppersMay 2–May 16
BasilApr 25–May 9
Butternut squashApr 25–May 9
CantaloupeMay 2–May 16
EggplantMay 2–May 16
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 21–Apr 4
OnionsMar 7–Mar 28
CarrotsMar 28–May 2
LettuceApr 4–Apr 25
BroccoliMar 21–Apr 4
BeetsMar 21–May 2
PeasMar 7–Mar 21
CabbageMar 21–Apr 4
RadishesMar 14–Apr 25
Brussels sproutsApr 4–Apr 18
SpinachMar 7–Mar 28
CilantroApr 4–Apr 25
KaleMar 21–Apr 4
Collard greensMar 21–Apr 4
TurnipsMar 21–Apr 4
DillApr 18–May 2
CeleryApr 25–May 2
CauliflowerApr 4–Apr 18
LeeksApr 4–Apr 18
Swiss chardApr 4–May 2
ParsleyApr 4–Apr 25
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 6–Nov 10
GarlicSep 29–Nov 3
Daffodil bulbsSep 22–Nov 3
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 21–Apr 4
AsparagusMar 21–Apr 4

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 4Apr 18May 2Oct 4Oct 20Nov 1
Hard freeze, 28°FMar 25Apr 8Apr 22Oct 16Oct 30Nov 11

Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.

Where these numbers come from

NOAA station Des Moines International Airport (USW00014933) sits 3.5 miles from the center of Des Moines at 957 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.

Questions

When is the last frost in Des Moines, IA?

The average last frost date in Des Moines is April 18, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 2.

When is the first frost in Des Moines?

The first frost in fall usually comes around October 20. One year in ten it arrives before October 4.

How long is the growing season in Des Moines?

About 184 days between the average last and first frost.

When should I plant tomatoes in Des Moines?

Plant tomato seedlings outside from April 25 to May 9. Start seeds indoors six to eight weeks earlier.

Nearby in Iowa

All 27 cities in Iowa