Frost dates for 19460Phoenixville, PA
The average last spring frost in Phoenixville is April 18 and the average first fall frost is October 27, giving a typical growing season of about 192 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Oct 27
- Growing season
- 192 days
Safer after May 4 (1-in-10 risk)
Possible by Oct 12 (1-in-10 risk)
Last frost typically in 166 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 17 · Apr 30 · May 17 | Oct 2 · Oct 15 · Nov 1 | 168 days | 100% |
| Frost / freeze (32°F) | Apr 3 · Apr 18 · May 4 | Oct 12 · Oct 27 · Nov 9 | 192 days | 100% |
| Hard freeze (28°F) | Mar 20 · Apr 3 · Apr 18 | Oct 24 · Nov 6 · Nov 23 | 217 days | 100% |
Planting calendar for Phoenixville
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 7 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 17 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 9 |
| Sweet corn | Sow outdoors | May 4 – Jul 7 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jun 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 19460 is matched to the NOAA station Phoenixville 1 E, PA, 2.9 km away, at 85 ft elevation (86 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Phoenixville 1 E, PA (used) | 85 ft | Apr 18 | Oct 27 |
| Pottstown Limerick Ap, PA | 291 ft | Apr 20 | Oct 23 |
| Graterford 1 E, PA | 279 ft | Apr 24 | Oct 15 |
| Norristown, PA | 62 ft | Apr 8 | Oct 31 |
Frost dates near Phoenixville
- Mont Clare, PA 19453 · last Apr 18, first Oct 27
- Kimberton, PA 19442 · last Apr 18, first Oct 27
- Oaks, PA 19456 · last Apr 18, first Oct 27
- Valley Forge, PA 19493 · last Apr 18, first Oct 27
- Devault, PA 19432 · last Apr 26, first Oct 18
- Spring City, PA 19475 · last Apr 20, first Oct 23
- Malvern, PA 19355 · last Apr 26, first Oct 18
- Royersford, PA 19468 · last Apr 20, first Oct 23
Frequently asked questions
- When is the last frost in Phoenixville, PA?
- For ZIP code 19460, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Phoenixville 1 E, PA weather station. There is a 1-in-10 chance of a frost after May 4.
- When is the first frost in Phoenixville, PA?
- The average first fall frost (32°F) is October 27. There is a 1-in-10 chance of frost by October 12, so tender plants are at risk from that point on.
- How long is the growing season in 19460?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 192 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.