Last frost date in Ballwin, MO

Average last frost
April 4

In Ballwin, the last spring frost comes around April 4 in an average year. Wait until April 21 if you want 90% odds of no more frost. The first fall frost usually arrives about October 29, which leaves 206 frost-free days. An early freeze before October 15 happens one year in ten.

Safe after (10% risk)
Apr 21
Average first frost
Oct 29
Frost-free season
206 days
Hard freeze (28°F) ends
Mar 25
Next 7 nights in Ballwin

No frost in the next 7 nights

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

  1. ThuOct 2249°
  2. FriOct 2347°
  3. SatOct 2449°
  4. SunOct 2551°
  5. MonOct 2650°
  6. TueOct 2747°
  7. WedOct 2849°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 4First frost Oct 29206 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND206 frost-free days
Frost risk through the year at St Charles 7 SSW, 6.4 miles from Ballwin.

Planting calendar for Ballwin

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 11–Apr 25
PumpkinsApr 18–May 2
SunflowersApr 4–Apr 25
CucumbersApr 18–Apr 25
CornApr 11–Apr 25
Sweet potatoesApr 25–May 9
WatermelonApr 18–May 2
Green beansApr 11–May 2
ZucchiniApr 11–Apr 25
OkraApr 25–May 9
PeppersApr 18–May 2
BasilApr 11–Apr 25
Butternut squashApr 11–Apr 25
CantaloupeApr 18–May 2
EggplantApr 18–May 2
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 7–Mar 21
OnionsFeb 21–Mar 14
CarrotsMar 14–Apr 18
LettuceMar 21–Apr 11
BroccoliMar 7–Mar 21
BeetsMar 7–Apr 18
PeasFeb 21–Mar 7
CabbageMar 7–Mar 21
RadishesFeb 28–Apr 11
Brussels sproutsMar 21–Apr 4
SpinachFeb 21–Mar 14
CilantroMar 21–Apr 11
KaleMar 7–Mar 21
Collard greensMar 7–Mar 21
TurnipsMar 7–Mar 21
DillApr 4–Apr 18
CeleryApr 11–Apr 18
CauliflowerMar 21–Apr 4
LeeksMar 21–Apr 4
Swiss chardMar 21–Apr 18
ParsleyMar 21–Apr 11
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 15–Nov 19
GarlicOct 8–Nov 12
Daffodil bulbsOct 1–Nov 12
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 7–Mar 21
AsparagusMar 7–Mar 21

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FMar 20Apr 4Apr 21Oct 15Oct 29Nov 11
Hard freeze, 28°FMar 8Mar 25Apr 8Oct 27Nov 8Nov 27

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 St Charles 7 SSW (USC00237398) sits 6.4 miles from the center of Ballwin at 450 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 Ballwin, MO?

The average last frost date in Ballwin is April 4, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 21.

When is the first frost in Ballwin?

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

How long is the growing season in Ballwin?

About 206 days between the average last and first frost.

When should I plant tomatoes in Ballwin?

Plant tomato seedlings outside from April 11 to April 25. Start seeds indoors six to eight weeks earlier.

Nearby in Missouri

All 41 cities in Missouri