Frost Dates for Pittsburgh, PA 15237

Last spring frost May 1 · First fall frost October 14 · 166 frost-free days · USDA Zone 6b

Frost probability for 15237

Frost10%50%90%
Spring (last frost)May 16May 1April 18
Fall (first frost)September 25October 14October 31

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (28.1 km away); the 50% date is the median year.

Frost dates by ZIP code in Pittsburgh, PA

ZIPLast spring frost (50%)First fall frost (50%)Zone
15237May 1October 146b
15235May 1October 146b
15236April 30October 176b
15213April 30October 176b
15221May 1October 146b
15206April 30October 176b
15227April 30October 176b
15212April 30October 176b
15217April 30October 176b
15210April 30October 176b
15205May 1October 176b
15241April 30October 176b
15216April 30October 176b
15239May 6October 126b
15202May 1October 176b
15228April 30October 176b
15220April 30October 176b
15229May 1October 146b
15214April 30October 176b
15234April 30October 176b
15226April 30October 176b
15243April 30October 176b
15218April 30October 176b
15201April 30October 177a
15238May 13October 76b
15209May 1October 146b
15215May 1October 146b
15219April 30October 176b
15232April 30October 176b
15207April 30October 176b
15211April 30October 176b
15224April 30October 176b
15203April 30October 177a
15208April 30October 176b
15204April 30October 177a
15223May 1October 146b
15282April 30October 176b
15222April 30October 177a
15233April 30October 177a
15225May 1October 177a
15275May 1October 17Zone 6a
15260April 30October 176b
15290April 30October 177a

Month by month in Pittsburgh

MonthWhat to do
JanuaryPlan your garden layout and order seeds. Research varieties suited to your frost dates.
FebruaryStart the slowest-growing crops indoors: onions, leeks, and celery (10–12 weeks before last frost).
MarchStart peppers and eggplant indoors 8–10 weeks before your last frost (around May 1). Start tomatoes about two weeks later, 6–8 weeks before last frost.
AprilStart herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
MayLast frost around May 1. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
JuneFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
JulySuccession plant lettuce and greens. Keep beds weeded and watered consistently.
AugustHarvest regularly to encourage production. Monitor for pests and disease.
SeptemberFirst fall frost approaching (around October 14). Transplant fall brassicas. Sow spinach, arugula, and radishes.
OctoberFirst frost around October 14. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
NovemberHarvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.
DecemberClean up spent plants. Add compost to beds. Rest, review, and plan next year's garden.

What grows in a 166-day season

Frequently Asked Questions

What is the last frost date for Pittsburgh, PA (ZIP 15237)?

The median last spring frost date for Pittsburgh, PA (ZIP code 15237) is around May 1. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in Pittsburgh, PA?

The median first fall frost date for Pittsburgh, PA is around October 14. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in Pittsburgh, PA?

The frost-free growing season in Pittsburgh is about 166 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is Pittsburgh, PA?

Based on frost date patterns, Pittsburgh falls approximately in 6b. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in Pittsburgh, PA?

Start tomato seeds indoors 6–8 weeks before your last frost date (around May 1). For Pittsburgh, that's roughly March 6 to March 20. Transplant outdoors 1–2 weeks after your last frost.

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