Last frost date in St. Charles, MO

Average last frost
April 8

In St. Charles, the last spring frost comes around April 8 in an average year. Wait until April 24 if you want 90% odds of no more frost. The first fall frost usually arrives about October 29, which leaves 203 frost-free days. An early freeze before October 16 happens one year in ten.

Safe after (10% risk)
Apr 24
Average first frost
Oct 29
Frost-free season
203 days
Hard freeze (28°F) ends
Mar 30
Next 7 nights in St. Charles

No frost in the next 7 nights

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

  1. ThuOct 2249°
  2. FriOct 2348°
  3. SatOct 2450°
  4. SunOct 2552°
  5. MonOct 2650°
  6. TueOct 2747°
  7. WedOct 2849°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 8First frost Oct 29203 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND203 frost-free days
Frost risk through the year at St Charles Elm Pt, 1.3 miles from St. Charles.

Planting calendar for St. Charles

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 15–Apr 29
PumpkinsApr 22–May 6
SunflowersApr 8–Apr 29
CucumbersApr 22–Apr 29
CornApr 15–Apr 29
Sweet potatoesApr 29–May 13
WatermelonApr 22–May 6
Green beansApr 15–May 6
ZucchiniApr 15–Apr 29
OkraApr 29–May 13
PeppersApr 22–May 6
BasilApr 15–Apr 29
Butternut squashApr 15–Apr 29
CantaloupeApr 22–May 6
EggplantApr 22–May 6
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 11–Mar 25
OnionsFeb 25–Mar 18
CarrotsMar 18–Apr 22
LettuceMar 25–Apr 15
BroccoliMar 11–Mar 25
BeetsMar 11–Apr 22
PeasFeb 25–Mar 11
CabbageMar 11–Mar 25
RadishesMar 4–Apr 15
Brussels sproutsMar 25–Apr 8
SpinachFeb 25–Mar 18
CilantroMar 25–Apr 15
KaleMar 11–Mar 25
Collard greensMar 11–Mar 25
TurnipsMar 11–Mar 25
DillApr 8–Apr 22
CeleryApr 15–Apr 22
CauliflowerMar 25–Apr 8
LeeksMar 25–Apr 8
Swiss chardMar 25–Apr 22
ParsleyMar 25–Apr 15
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 15–Nov 19
GarlicOct 8–Nov 12
Daffodil bulbsOct 1–Nov 12
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 11–Mar 25
AsparagusMar 11–Mar 25

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FMar 23Apr 8Apr 24Oct 16Oct 29Nov 12
Hard freeze, 28°FMar 9Mar 30Apr 15Oct 29Nov 10Nov 28

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 Elm Pt (USC00237397) sits 1.3 miles from the center of St. Charles at 472 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 St. Charles, MO?

The average last frost date in St. Charles is April 8, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 24.

When is the first frost in St. Charles?

The first frost in fall usually comes around October 29. One year in ten it arrives before October 16.

How long is the growing season in St. Charles?

About 203 days between the average last and first frost.

When should I plant tomatoes in St. Charles?

Plant tomato seedlings outside from April 15 to April 29. Start seeds indoors six to eight weeks earlier.

Nearby in Missouri

All 41 cities in Missouri