Last frost date in Penn Hills, PA

Average last frost
April 16

Expect the last frost in Penn Hills around April 16. Frost after May 4 happens in only one year out of ten. The first fall frost usually arrives about November 1, which leaves 197 frost-free days. An early freeze before October 18 happens one year in ten.

Safe after (10% risk)
May 4
Average first frost
Nov 1
Frost-free season
197 days
Hard freeze (28°F) ends
Apr 3
Next 7 nights in Penn Hills

Frost possible in low spots Fri night, low 34°F

Earlier than usual: the average first frost here is November 1.

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

  1. ThuOct 2240°
  2. FriOct 2334°possible frost
  3. SatOct 2433°possible frost
  4. SunOct 2537°
  5. MonOct 2642°
  6. TueOct 2744°
  7. WedOct 2842°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 16First frost Nov 1197 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND197 frost-free days
Frost risk through the year at Acmetonia Lock 3, 4.1 miles from Penn Hills.

Planting calendar for Penn Hills

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 23–May 7
PumpkinsApr 30–May 14
SunflowersApr 16–May 7
CucumbersApr 30–May 7
CornApr 23–May 7
Sweet potatoesMay 7–May 21
WatermelonApr 30–May 14
Green beansApr 23–May 14
ZucchiniApr 23–May 7
OkraMay 7–May 21
PeppersApr 30–May 14
BasilApr 23–May 7
Butternut squashApr 23–May 7
CantaloupeApr 30–May 14
EggplantApr 30–May 14
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 19–Apr 2
OnionsMar 5–Mar 26
CarrotsMar 26–Apr 30
LettuceApr 2–Apr 23
BroccoliMar 19–Apr 2
BeetsMar 19–Apr 30
PeasMar 5–Mar 19
CabbageMar 19–Apr 2
RadishesMar 12–Apr 23
Brussels sproutsApr 2–Apr 16
SpinachMar 5–Mar 26
CilantroApr 2–Apr 23
KaleMar 19–Apr 2
Collard greensMar 19–Apr 2
TurnipsMar 19–Apr 2
DillApr 16–Apr 30
CeleryApr 23–Apr 30
CauliflowerApr 2–Apr 16
LeeksApr 2–Apr 16
Swiss chardApr 2–Apr 30
ParsleyApr 2–Apr 23
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 18–Nov 22
GarlicOct 11–Nov 15
Daffodil bulbsOct 4–Nov 15
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 19–Apr 2
AsparagusMar 19–Apr 2

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FMar 31Apr 16May 4Oct 18Nov 1Nov 13
Hard freeze, 28°FMar 19Apr 3Apr 19Nov 1Nov 11Nov 25

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 Acmetonia Lock 3 (USC00360022) sits 4.1 miles from the center of Penn Hills at 748 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 Penn Hills, PA?

The average last frost date in Penn Hills is April 16, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 4.

When is the first frost in Penn Hills?

The first frost in fall usually comes around November 1. One year in ten it arrives before October 18.

How long is the growing season in Penn Hills?

About 197 days between the average last and first frost.

When should I plant tomatoes in Penn Hills?

Plant tomato seedlings outside from April 23 to May 7. Start seeds indoors six to eight weeks earlier.

Nearby in Pennsylvania

All 35 cities in Pennsylvania