In Philadelphia, PA, the average last spring frost is Apr 2 and the average first fall frost is Nov 10, which leaves about 224 frost-free days for the garden. These dates come from NOAA climate normals for the Philadelphia International Airport, PA weather station, at 10 feet above sea level.
A long season lets you do more than one planting: a spring crop, a second planting of quick crops in summer, and a fall garden. Succession planting works well here. Frost timing varies from year to year: in about 1 spring in 10 the last frost falls as late as Apr 13, and in about 1 fall in 10 the first frost arrives as early as Oct 30.
Frost dates for Philadelphia, PA
| Chance of a freeze (32°F) after or before this date | Last spring frost | First fall frost | Freeze-free season |
|---|---|---|---|
| Optimistic (about 1 year in 10) | Mar 19 | Nov 24 | 250 days |
| Average (half of years) | Apr 2 | Nov 10 | 224 days |
| Cautious (9 years in 10 are safe) | Apr 13 | Oct 30 | 200 days |
Source: NOAA NCEI U.S. Climate Normals, 1991 to 2020. Use the cautious dates for tender crops such as tomatoes and peppers.
When to plant in Philadelphia, PA
These windows count weeks forward and back from the average frost dates above. They are planning guides: check the forecast before planting tender crops, and see our what to plant now tool for today's date.
| Crop | Start seeds indoors | Plant outdoors in spring | Plant in fall |
|---|---|---|---|
| Tomatoes | Feb 5 to Feb 19 | Apr 9 to Apr 16 | – |
| Peppers | Jan 22 to Feb 5 | Apr 16 to Apr 23 | – |
| Eggplant | Jan 22 to Feb 5 | Apr 16 to Apr 23 | – |
| Onions | Jan 22 to Feb 5 | Mar 5 to Mar 19 | – |
| Parsley | Jan 22 to Feb 5 | Apr 2 to Apr 9 | – |
| Broccoli, cabbage, cauliflower | Feb 5 to Feb 19 | Mar 19 to Mar 26 | Aug 18 to Sep 15 |
| Basil | Feb 19 to Feb 19 | Apr 9 to Apr 16 | – |
| Peas | Sow outdoors | Feb 19 to Mar 5 | Aug 18 to Sep 15 |
| Spinach | Sow outdoors | Feb 19 to Mar 5 | Sep 15 to Oct 13 |
| Radishes | Sow outdoors | Feb 19 to Mar 5 | Sep 15 to Oct 13 |
| Lettuce | Sow outdoors | Mar 5 to Mar 19 | Sep 15 to Oct 13 |
| Carrots | Sow outdoors | Mar 5 to Mar 19 | Aug 18 to Sep 15 |
| Beets | Sow outdoors | Mar 5 to Mar 19 | Aug 18 to Sep 15 |
| Potatoes | Sow outdoors | Mar 5 to Mar 19 | – |
| Kale | Sow outdoors | Mar 5 to Mar 19 | Aug 18 to Sep 15 |
| Swiss chard | Sow outdoors | Mar 19 to Apr 2 | – |
| Cilantro | Sow outdoors | Mar 19 to Apr 2 | Sep 15 to Oct 13 |
| Dill | Sow outdoors | Apr 2 to Apr 9 | – |
| Bush beans | Sow outdoors | Apr 9 to Apr 16 | Aug 7 to Aug 21 |
| Pole beans | Sow outdoors | Apr 9 to Apr 16 | – |
| Sweet corn | Sow outdoors | Apr 9 to Apr 16 | – |
| Cucumbers | Sow outdoors | Apr 9 to Apr 16 | Jul 28 to Aug 11 |
| Zucchini and summer squash | Sow outdoors | Apr 9 to Apr 16 | Aug 7 to Aug 21 |
| Winter squash | Sow outdoors | Apr 9 to Apr 16 | – |
| Sweet potatoes (slips) | Sow outdoors | Apr 16 to Apr 30 | – |
| Okra | Sow outdoors | Apr 16 to Apr 30 | – |
A dash in the fall column means the crop is not usually planted in fall, or the season is too short.
Overnight lows this week
The National Weather Service forecast shows frost risk on: Sun 15 night (35°F), Mon 16 night (34°F). Cover tender plants before dark on those nights.
| Night | Forecast low | Frost risk |
|---|---|---|
| Sat 14 night | 38°F | No frost expected |
| Sun 15 night | 35°F | Frost possible |
| Mon 16 night | 34°F | Frost possible |
| Tue 17 night | 37°F | No frost expected |
| Wed 18 night | 37°F | No frost expected |
| Thu 19 night | 40°F | No frost expected |
| Fri 20 night | 42°F | No frost expected |
Live forecast for the station location, from the National Weather Service. For your own ZIP code, use our garden weather forecast.
More garden tools for Philadelphia, PA
- Frost dates by ZIP code for your exact location
- What to plant now, based on today's date
- Garden weather forecast by ZIP code
- Safe transplant date calculator
Frequently asked questions
When is the last frost in Philadelphia, PA?
The average last spring frost is Apr 2. A late frost as far out as Apr 13 happens in about 1 year in 10, so tender plants such as tomatoes and peppers are safest after that cautious date.
When is the first frost in Philadelphia, PA?
The average first fall frost is Nov 10. It can arrive as early as Oct 30 in about 1 year in 10, so plan to harvest tender crops before then.
How long is the growing season in Philadelphia, PA?
The average freeze-free season is about 224 days, between the average last spring frost and the average first fall frost.
Where do these dates come from?
They come from the NOAA 1991 to 2020 U.S. Climate Normals for the Philadelphia International Airport, PA station. Hills, valleys, lakes and city heat can shift frost by a week or more, so compare with neighbors who garden near you.