Frost dates for 19151 — Philadelphia, PA
How Philadelphia compares
- In 8 years out of 10, the last spring frost in Philadelphia falls between March 15 and April 12, a 28-day window. The first fall frost falls between November 4 and December 4.
- The median last frost is 28 days earlier than the Pennsylvania median of Apr 27.
- Its 232-day growing season is among the longest of the 1,787 Pennsylvania places with a regular frost season.
- The last frost is 6 days earlier than the zone 7b median of Apr 5. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7b chart.
- The weather station records an average of 62 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 15 |
| 50% (median) | March 30 |
| 10% (safe for tender plants) | April 12 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 4 |
| 50% (median) | November 17 |
| 90% (late) | December 4 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Philadelphia, PA
Frost dates for 19151 — Philadelphia, PA — last frost Mar 30, first frost Nov 17, zone 7b. whenisthelastfrost.com
When to plant vegetables in Philadelphia, PA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 5 – Jan 19 | Mar 2 – Mar 16 | — | — |
| Peppers | Jan 19 – Feb 2 | Apr 13 – Apr 27 | — | — |
| Eggplant | Jan 19 – Feb 2 | Apr 13 – Apr 27 | — | — |
| Tomatoes | Feb 2 – Feb 16 | Apr 6 – Apr 20 | — | — |
| Lettuce | Feb 2 – Feb 16 | Mar 9 – Mar 23 | Mar 2 – Apr 6 | Sep 22 – Oct 20 |
| Kale | Feb 2 – Feb 16 | Mar 2 – Mar 16 | Mar 2 – Mar 16 | Sep 8 – Sep 29 |
| Broccoli | Feb 2 – Feb 16 | Mar 16 – Mar 30 | — | Aug 11 – Sep 1 |
| Cabbage | Feb 2 – Feb 16 | Mar 9 – Mar 23 | — | Aug 11 – Sep 1 |
| Cauliflower | Feb 2 – Feb 16 | Mar 16 – Mar 30 | — | Aug 11 – Sep 1 |
| Okra | Feb 16 – Mar 2 | Apr 20 – May 4 | Apr 20 – May 4 | — |
| Basil | Feb 16 – Mar 2 | Apr 6 – Apr 20 | — | — |
| Peas | — | — | Feb 16 – Mar 9 | Aug 25 – Sep 15 |
| Spinach | — | — | Feb 16 – Mar 9 | Sep 22 – Oct 13 |
| Radishes | — | — | Feb 23 – Apr 6 | Oct 6 – Oct 27 |
| Cucumbers | Mar 2 – Mar 9 | Apr 13 – Apr 20 | Apr 6 – Apr 20 | Sep 1 – Sep 15 |
| Zucchini & Summer Squash | Mar 2 – Mar 9 | — | Apr 6 – Apr 20 | Sep 8 – Sep 22 |
| Winter Squash & Pumpkins | Mar 2 – Mar 9 | — | Apr 6 – Apr 20 | — |
| Melons & Watermelon | Mar 2 – Mar 9 | Apr 13 – Apr 27 | — | — |
| Carrots | — | — | Mar 9 – Apr 6 | Aug 25 – Sep 8 |
| Beets | — | — | Mar 9 – Apr 6 | Sep 8 – Sep 22 |
| Potatoes | — | — | Mar 9 – Mar 30 | — |
| Swiss Chard | — | — | Mar 16 – Apr 13 | Sep 8 – Sep 22 |
| Cilantro | — | — | Mar 16 – Apr 6 | Sep 22 – Oct 13 |
| Green Beans | — | — | Apr 6 – Apr 27 | Sep 1 – Sep 15 |
| Sweet Corn | — | — | Apr 6 – Apr 20 | — |
| Sweet Potatoes | — | Apr 13 – May 4 | — | — |
| Garlic | — | — | — | Nov 3 – Dec 8 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Phila Franklin Inst, PA weather station, 7 km away (elevation 59 ft (18 m)).
ZIP codes in Philadelphia: 19019 19092 19093 19099 19101 19102 19103 19104 19105 19106 19107 19108 19109 19110 19111 19112 19113 19114 19115 19116 19118 19119 19120 19121 19122 19123 19124 19125 19126 19127 19128 19129 19130 19131 19132 19133 19134 19135 19136 19137 19138 19139 19140 19141 19142 19143 19144 19145 19146 19147 19148 19149 19150 19151 19152 19153 19154 19155 19160 19161 …
Frost dates near Philadelphia
- Upper Darby Mar 30 · Nov 17
- Merion Station Mar 30 · Nov 17
- Wynnewood Mar 30 · Nov 17
- Bala Cynwyd Mar 30 · Nov 17
- Lansdowne Mar 30 · Nov 17
- Narberth Mar 30 · Nov 17
- Ardmore Mar 30 · Nov 17
- Havertown Mar 30 · Nov 17
Frequently asked questions
When is the last frost in Philadelphia, PA?
The median last spring frost in Philadelphia, PA is March 30. There is still about a 10% chance of frost after April 12, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Philadelphia, PA?
The median first fall frost is November 17, with about a 10% chance of frost before November 4.
How long is the growing season in Philadelphia, PA?
About 232 days between the median last spring frost and first fall frost.
What planting zone is Philadelphia, PA?
Philadelphia, PA is in USDA hardiness zone 7b.