Philadelphia, PA Frost Dates & Growing Season

The two dates every Philadelphia garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Mar 30
~50% chance of frost after
First fall frost
Nov 17
~50% chance of frost before
Growing season
232 days
frost-free stretch
USDA zone
7b
2023 hardiness map
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Mar 15 Mar 30 Apr 12
First fall frost Dec 4 Nov 17 Nov 4
Hard freeze (28°F), median last Mar 17 · first Nov 29

Computed from NOAA 1991–2020 climate normals at the Phila Franklin Inst station (1 km from central Philadelphia). "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Philadelphia

Computed from Philadelphia's own frost dates. Click any crop for the full zone-7 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Feb 2 – Feb 16 Apr 6 – Apr 13
🫑 Peppers Jan 19 – Feb 2 Apr 13 – Apr 20
🥬 Lettuce Feb 16 – Mar 2 Mar 2 – Mar 16 Mar 2 – Mar 30
🫛 Peas Feb 16 – Mar 2
🥕 Carrots Mar 9 – Mar 30
🥦 Broccoli Feb 9 – Feb 23 Mar 9 – Mar 23
🥬 Kale Feb 16 – Mar 2 Mar 2 – Mar 16 Mar 2 – Mar 16
🥒 Cucumbers Mar 2 – Mar 9 Apr 6 – Apr 13 Apr 6 – Apr 13
🥒 Zucchini Mar 2 – Mar 9 Apr 6 – Apr 13 Apr 6 – Apr 13
🫘 Green Beans (Bush) Apr 6 – Apr 13
🌽 Sweet Corn Apr 6 – Apr 13
🌿 Basil Feb 16 – Mar 2 Apr 6 – Apr 13 Apr 13 – Apr 20
🧄 Garlic Fall: Oct 6 – Nov 3

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Philadelphia's dates automatically after a lookup.

Reading the season in Philadelphia

With roughly 232 frost-free days, Philadelphia gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Nov 17 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Philadelphia, PA?

The average last spring frost in Philadelphia is around Mar 30, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Philadelphia, PA?

The average first fall frost in Philadelphia arrives around Nov 17. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Philadelphia?

About 232 frost-free days on average, from Mar 30 to Nov 17. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Philadelphia in?

USDA zone 7b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.