Last frost date in Middleton, WI

Average last frost
April 28

Expect the last frost in Middleton around April 28. Frost after May 11 happens in only one year out of ten. The first fall frost usually arrives about October 15, which leaves 169 frost-free days. An early freeze before September 29 happens one year in ten.

Safe after (10% risk)
May 11
Average first frost
Oct 15
Frost-free season
169 days
Hard freeze (28°F) ends
Apr 17
Next 7 nights in Middleton

No frost in the next 7 nights

Later than usual: the average first frost here is October 15.

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

  1. ThuOct 2249°
  2. FriOct 2351°
  3. SatOct 2453°
  4. SunOct 2549°
  5. MonOct 2643°
  6. TueOct 2741°
  7. WedOct 2842°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 28First frost Oct 15169 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND169 frost-free days
Frost risk through the year at Charmany Farm, 3.5 miles from Middleton.

Planting calendar for Middleton

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesMay 5–May 19
PumpkinsMay 12–May 26
SunflowersApr 28–May 19
CucumbersMay 12–May 19
CornMay 5–May 19
Sweet potatoesMay 19–Jun 2
WatermelonMay 12–May 26
Green beansMay 5–May 26
ZucchiniMay 5–May 19
OkraMay 19–Jun 2
PeppersMay 12–May 26
BasilMay 5–May 19
Butternut squashMay 5–May 19
CantaloupeMay 12–May 26
EggplantMay 12–May 26
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 31–Apr 14
OnionsMar 17–Apr 7
CarrotsApr 7–May 12
LettuceApr 14–May 5
BroccoliMar 31–Apr 14
BeetsMar 31–May 12
PeasMar 17–Mar 31
CabbageMar 31–Apr 14
RadishesMar 24–May 5
Brussels sproutsApr 14–Apr 28
SpinachMar 17–Apr 7
CilantroApr 14–May 5
KaleMar 31–Apr 14
Collard greensMar 31–Apr 14
TurnipsMar 31–Apr 14
DillApr 28–May 12
CeleryMay 5–May 12
CauliflowerApr 14–Apr 28
LeeksApr 14–Apr 28
Swiss chardApr 14–May 12
ParsleyApr 14–May 5
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 1–Nov 5
GarlicSep 24–Oct 29
Daffodil bulbsSep 17–Oct 29
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 31–Apr 14
AsparagusMar 31–Apr 14

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 14Apr 28May 11Sep 29Oct 15Oct 29
Hard freeze, 28°FApr 4Apr 17May 1Oct 10Oct 25Nov 6

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 Charmany Farm (USC00471416) sits 3.5 miles from the center of Middleton at 1,046 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 Middleton, WI?

The average last frost date in Middleton is April 28, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 11.

When is the first frost in Middleton?

The first frost in fall usually comes around October 15. One year in ten it arrives before September 29.

How long is the growing season in Middleton?

About 169 days between the average last and first frost.

When should I plant tomatoes in Middleton?

Plant tomato seedlings outside from May 5 to May 19. Start seeds indoors six to eight weeks earlier.

Nearby in Wisconsin

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