Frost dates for 19113Philadelphia, PA
The average last spring frost in Philadelphia is April 2 and the average first fall frost is November 10, giving a typical growing season of about 224 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Nov 10
- Growing season
- 224 days
Safer after Apr 13 (1-in-10 risk)
Possible by Oct 30 (1-in-10 risk)
First frost typically in 7 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 1 · Apr 13 · Apr 28 | Oct 18 · Oct 31 · Nov 12 | 200 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 2 · Apr 13 | Oct 30 · Nov 10 · Nov 24 | 224 days | 100% |
| Hard freeze (28°F) | Mar 7 · Mar 22 · Apr 3 | Nov 7 · Nov 23 · Dec 8 | 246 days | 100% |
Planting calendar for Philadelphia
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 21 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Jul 31 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 23 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 21 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 11 – Jul 21 |
| Broccoli | Transplant outdoors (fall) | Aug 10 – Aug 21 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jul 1 – Jul 31 |
| Cabbage | Transplant outdoors (fall) | Jul 31 – Aug 31 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 31 – Sep 16 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 17 – Sep 21 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Jul 31 – Oct 1 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 24 – Aug 31 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jul 1 – Aug 16 |
| Garlic | Plant outdoors (fall) | Oct 31 – Dec 1 |
Where these dates come from
ZIP code 19113 is matched to the NOAA station Philadelphia Intl Ap, PA, 3.8 km away, at 10 ft elevation (10 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Philadelphia Intl Ap, PA (used) | 10 ft | Apr 2 | Nov 10 |
| Phila Franklin Inst, PA | 60 ft | Mar 30 | Nov 17 |
| Marcus Hook, PA | 10 ft | Mar 30 | Nov 16 |
| Glassboro 2 Ne, NJ | 100 ft | Apr 8 | Nov 1 |
Frost dates near Philadelphia
- Essington, PA 19029 · last Apr 2, first Nov 10
- Folcroft, PA 19032 · last Apr 2, first Nov 10
- Norwood, PA 19074 · last Apr 2, first Nov 10
- Prospect Park, PA 19076 · last Apr 2, first Nov 10
- Ridley Park, PA 19078 · last Apr 2, first Nov 10
- Sharon Hill, PA 19079 · last Apr 2, first Nov 10
- Holmes, PA 19098 · last Apr 2, first Nov 10
- Gibbstown, NJ 08027 · last Apr 2, first Nov 10
Frequently asked questions
- When is the last frost in Philadelphia, PA?
- For ZIP code 19113, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the Philadelphia Intl Ap, PA weather station. There is a 1-in-10 chance of a frost after April 13.
- When is the first frost in Philadelphia, PA?
- The average first fall frost (32°F) is November 10. There is a 1-in-10 chance of frost by October 30, so tender plants are at risk from that point on.
- How long is the growing season in 19113?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 224 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.