Last frost date in Mason, OH

Average last frost
April 22

The average last frost in Mason is April 22. By May 10 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 18, which leaves 178 frost-free days. An early freeze before October 5 happens one year in ten.

Safe after (10% risk)
May 10
Average first frost
Oct 18
Frost-free season
178 days
Hard freeze (28°F) ends
Apr 8
Next 7 nights in Mason

No frost in the next 7 nights

Later than usual: the average first frost here is October 18.

National Weather Service forecast, updated Oct 22, 12:24 UTC

  1. ThuOct 2242°
  2. FriOct 2341°
  3. SatOct 2441°
  4. SunOct 2543°
  5. MonOct 2645°
  6. TueOct 2747°
  7. WedOct 2844°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 22First frost Oct 18178 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND178 frost-free days
Frost risk through the year at Hamilton Butler County Regional Airport, 12.2 miles from Mason.

Planting calendar for Mason

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 29–May 13
PumpkinsMay 6–May 20
SunflowersApr 22–May 13
CucumbersMay 6–May 13
CornApr 29–May 13
Sweet potatoesMay 13–May 27
WatermelonMay 6–May 20
Green beansApr 29–May 20
ZucchiniApr 29–May 13
OkraMay 13–May 27
PeppersMay 6–May 20
BasilApr 29–May 13
Butternut squashApr 29–May 13
CantaloupeMay 6–May 20
EggplantMay 6–May 20
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 25–Apr 8
OnionsMar 11–Apr 1
CarrotsApr 1–May 6
LettuceApr 8–Apr 29
BroccoliMar 25–Apr 8
BeetsMar 25–May 6
PeasMar 11–Mar 25
CabbageMar 25–Apr 8
RadishesMar 18–Apr 29
Brussels sproutsApr 8–Apr 22
SpinachMar 11–Apr 1
CilantroApr 8–Apr 29
KaleMar 25–Apr 8
Collard greensMar 25–Apr 8
TurnipsMar 25–Apr 8
DillApr 22–May 6
CeleryApr 29–May 6
CauliflowerApr 8–Apr 22
LeeksApr 8–Apr 22
Swiss chardApr 8–May 6
ParsleyApr 8–Apr 29
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 4–Nov 8
GarlicSep 27–Nov 1
Daffodil bulbsSep 20–Nov 1
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 25–Apr 8
AsparagusMar 25–Apr 8

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 6Apr 22May 10Oct 5Oct 18Oct 29
Hard freeze, 28°FMar 26Apr 8Apr 28Oct 15Oct 27Nov 8

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 Hamilton Butler County Regional Airport (USW00053855) sits 12.2 miles from the center of Mason at 634 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 Mason, OH?

The average last frost date in Mason is April 22, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 10.

When is the first frost in Mason?

The first frost in fall usually comes around October 18. One year in ten it arrives before October 5.

How long is the growing season in Mason?

About 178 days between the average last and first frost.

When should I plant tomatoes in Mason?

Plant tomato seedlings outside from April 29 to May 13. Start seeds indoors six to eight weeks earlier.

Nearby in Ohio

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