Last frost date in Mount Lebanon, PA

Average last frost
April 18

Expect the last frost in Mount Lebanon around April 18. Frost after May 6 happens in only one year out of ten. The first fall frost usually arrives about October 28, which leaves 193 frost-free days. An early freeze before October 14 happens one year in ten.

Safe after (10% risk)
May 6
Average first frost
Oct 28
Frost-free season
193 days
Hard freeze (28°F) ends
Apr 5
Next 7 nights in Mount Lebanon

Frost possible in low spots Fri night, low 36°F

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

  1. ThuOct 2241°
  2. FriOct 2336°possible frost
  3. SatOct 2435°possible frost
  4. SunOct 2538°
  5. MonOct 2643°
  6. TueOct 2746°
  7. WedOct 2844°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 18First frost Oct 28193 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND193 frost-free days
Frost risk through the year at Pittsburgh Allegheny County Airport, 6.9 miles from Mount Lebanon.

Planting calendar for Mount Lebanon

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 25–May 9
PumpkinsMay 2–May 16
SunflowersApr 18–May 9
CucumbersMay 2–May 9
CornApr 25–May 9
Sweet potatoesMay 9–May 23
WatermelonMay 2–May 16
Green beansApr 25–May 16
ZucchiniApr 25–May 9
OkraMay 9–May 23
PeppersMay 2–May 16
BasilApr 25–May 9
Butternut squashApr 25–May 9
CantaloupeMay 2–May 16
EggplantMay 2–May 16
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 21–Apr 4
OnionsMar 7–Mar 28
CarrotsMar 28–May 2
LettuceApr 4–Apr 25
BroccoliMar 21–Apr 4
BeetsMar 21–May 2
PeasMar 7–Mar 21
CabbageMar 21–Apr 4
RadishesMar 14–Apr 25
Brussels sproutsApr 4–Apr 18
SpinachMar 7–Mar 28
CilantroApr 4–Apr 25
KaleMar 21–Apr 4
Collard greensMar 21–Apr 4
TurnipsMar 21–Apr 4
DillApr 18–May 2
CeleryApr 25–May 2
CauliflowerApr 4–Apr 18
LeeksApr 4–Apr 18
Swiss chardApr 4–May 2
ParsleyApr 4–Apr 25
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 14–Nov 18
GarlicOct 7–Nov 11
Daffodil bulbsSep 30–Nov 11
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 21–Apr 4
AsparagusMar 21–Apr 4

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 2Apr 18May 6Oct 14Oct 28Nov 10
Hard freeze, 28°FMar 23Apr 5Apr 21Oct 28Nov 8Nov 22

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 Pittsburgh Allegheny County Airport (USW00014762) sits 6.9 miles from the center of Mount Lebanon at 1,248 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 Mount Lebanon, PA?

The average last frost date in Mount Lebanon is April 18, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 6.

When is the first frost in Mount Lebanon?

The first frost in fall usually comes around October 28. One year in ten it arrives before October 14.

How long is the growing season in Mount Lebanon?

About 193 days between the average last and first frost.

When should I plant tomatoes in Mount Lebanon?

Plant tomato seedlings outside from April 25 to May 9. Start seeds indoors six to eight weeks earlier.

Nearby in Pennsylvania

All 35 cities in Pennsylvania