Last frost date in Willmar, MN

Average last frost
April 30

Expect the last frost in Willmar around April 30. Frost after May 13 happens in only one year out of ten. The first fall frost usually arrives about October 7, which leaves 159 frost-free days. An early freeze before September 23 happens one year in ten.

Safe after (10% risk)
May 13
Average first frost
Oct 7
Frost-free season
159 days
Hard freeze (28°F) ends
Apr 19
Next 7 nights in Willmar

Frost possible in low spots Mon night, low 34°F

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

  1. ThuOct 2254°
  2. FriOct 2359°
  3. SatOct 2442°
  4. SunOct 2537°
  5. MonOct 2634°possible frost
  6. TueOct 2736°possible frost
  7. WedOct 2838°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 30First frost Oct 7159 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND159 frost-free days
Frost risk through the year at Willmar Wwtp, 1.4 miles from Willmar.

Planting calendar for Willmar

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesMay 7–May 21
PumpkinsMay 14–May 28
SunflowersApr 30–May 21
CucumbersMay 14–May 21
CornMay 7–May 21
Sweet potatoesMay 21–Jun 4
WatermelonMay 14–May 28
Green beansMay 7–May 28
ZucchiniMay 7–May 21
OkraMay 21–Jun 4
PeppersMay 14–May 28
BasilMay 7–May 21
Butternut squashMay 7–May 21
CantaloupeMay 14–May 28
EggplantMay 14–May 28
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesApr 2–Apr 16
OnionsMar 19–Apr 9
CarrotsApr 9–May 14
LettuceApr 16–May 7
BroccoliApr 2–Apr 16
BeetsApr 2–May 14
PeasMar 19–Apr 2
CabbageApr 2–Apr 16
RadishesMar 26–May 7
Brussels sproutsApr 16–Apr 30
SpinachMar 19–Apr 9
CilantroApr 16–May 7
KaleApr 2–Apr 16
Collard greensApr 2–Apr 16
TurnipsApr 2–Apr 16
DillApr 30–May 14
CeleryMay 7–May 14
CauliflowerApr 16–Apr 30
LeeksApr 16–Apr 30
Swiss chardApr 16–May 14
ParsleyApr 16–May 7
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsSep 23–Oct 28
GarlicSep 16–Oct 21
Daffodil bulbsSep 9–Oct 21
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesApr 2–Apr 16
AsparagusApr 2–Apr 16

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 16Apr 30May 13Sep 23Oct 7Oct 21
Hard freeze, 28°FApr 5Apr 19May 2Oct 2Oct 19Oct 31

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 Willmar Wwtp (USC00219004) sits 1.4 miles from the center of Willmar at 1,100 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 Willmar, MN?

The average last frost date in Willmar is April 30, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 13.

When is the first frost in Willmar?

The first frost in fall usually comes around October 7. One year in ten it arrives before September 23.

How long is the growing season in Willmar?

About 159 days between the average last and first frost.

When should I plant tomatoes in Willmar?

Plant tomato seedlings outside from May 7 to May 21. Start seeds indoors six to eight weeks earlier.

Nearby in Minnesota

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