Frost dates for 18920Erwinna, PA
The average last spring frost in Erwinna is April 29 and the average first fall frost is October 16, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 16
- Growing season
- 170 days
Safer after May 15 (1-in-10 risk)
Possible by Oct 4 (1-in-10 risk)
Last frost typically in 177 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 26 · May 10 · May 25 | Sep 26 · Oct 6 · Oct 19 | 149 days | 100% |
| Frost / freeze (32°F) | Apr 16 · Apr 29 · May 15 | Oct 4 · Oct 16 · Nov 1 | 170 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 17 · May 2 | Oct 12 · Oct 28 · Nov 8 | 193 days | 100% |
Planting calendar for Erwinna
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 26 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 6 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 29 |
| Sweet corn | Sow outdoors | May 15 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 18920 is matched to the NOAA station Bucksville, PA, 10.5 km away, at 387 ft elevation (220 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Bucksville, PA (used) | 387 ft | Apr 29 | Oct 16 |
| Springtown 1 Nne, PA | 860 ft | Apr 21 | Oct 22 |
| Flemington 5 Nnw, NJ | 265 ft | Apr 24 | Oct 21 |
| Lambertville, NJ | 68 ft | Apr 16 | Oct 19 |
Frost dates near Erwinna
- Frenchtown, NJ 08825 · last Apr 29, first Oct 16
- Upper Black Eddy, PA 18972 · last Apr 29, first Oct 16
- Baptistown, NJ 08803 · last Apr 29, first Oct 16
- Revere, PA 18953 · last Apr 29, first Oct 16
- Ottsville, PA 18942 · last Apr 29, first Oct 16
- Ferndale, PA 18921 · last Apr 29, first Oct 16
- Pipersville, PA 18947 · last Apr 13, first Oct 30
- Milford, NJ 08848 · last Apr 29, first Oct 16
Frequently asked questions
- When is the last frost in Erwinna, PA?
- For ZIP code 18920, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Bucksville, PA weather station. There is a 1-in-10 chance of a frost after May 15.
- When is the first frost in Erwinna, PA?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by October 4, so tender plants are at risk from that point on.
- How long is the growing season in 18920?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 170 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.