Frost dates for 18351Portland, PA
The average last spring frost in Portland is April 30 and the average first fall frost is October 18, giving a typical growing season of about 168 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 30
- Average first fall frost
- Oct 18
- Growing season
- 168 days
Safer after May 18 (1-in-10 risk)
Possible by Oct 3 (1-in-10 risk)
Last frost typically in 178 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 12 · May 29 | Sep 25 · Oct 6 · Oct 20 | 147 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 30 · May 18 | Oct 3 · Oct 18 · Nov 1 | 168 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 16 · May 5 | Oct 14 · Oct 29 · Nov 10 | 195 days | 100% |
Planting calendar for Portland
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 30 – Jun 5 |
| Tomatoes | Transplant outdoors | May 16 – Jun 28 |
| Peppers | Start seeds indoors | Mar 30 – Apr 30 |
| Peppers | Transplant outdoors | May 30 – Jun 30 |
| Eggplant | Start seeds indoors | Apr 16 – May 15 |
| Eggplant | Transplant outdoors | May 30 – Jun 30 |
| Cucumbers | Sow outdoors | May 30 – Jul 8 |
| Summer squash | Sow outdoors | May 16 – Jun 30 |
| Winter squash & pumpkins | Sow outdoors | May 30 – Jun 30 |
| Snap beans | Sow outdoors | May 16 – Jul 31 |
| Sweet corn | Sow outdoors | May 16 – Jun 28 |
| Watermelon & cantaloupe | Sow outdoors | May 30 – Jun 30 |
| Okra | Sow outdoors | May 23 – Jun 15 |
| Peas | Sow outdoors (spring) | Mar 30 – May 15 |
| Potatoes | Plant outdoors (spring) | Mar 30 – May 30 |
| Onions | Start seeds indoors (spring) | Feb 16 – Mar 15 |
| Onions | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (spring) | Mar 12 – Apr 15 |
| Broccoli | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (fall) | Jun 18 – Jun 28 |
| Broccoli | Transplant outdoors (fall) | Jul 18 – Jul 29 |
| Cabbage | Start seeds indoors (spring) | Mar 2 – Mar 30 |
| Cabbage | Transplant outdoors (spring) | Mar 30 – Apr 30 |
| Cabbage | Start seeds indoors (fall) | Jun 8 – Jul 8 |
| Cabbage | Transplant outdoors (fall) | Jul 8 – Aug 8 |
| Leaf lettuce | Sow outdoors (spring) | Mar 30 – Jun 15 |
| Leaf lettuce | Sow outdoors (fall) | Jul 8 – Aug 24 |
| Spinach | Sow outdoors (spring) | Mar 23 – May 6 |
| Spinach | Sow outdoors (fall) | Jul 25 – Aug 29 |
| Radishes | Sow outdoors (spring) | Mar 30 – May 20 |
| Radishes | Sow outdoors (fall) | Jul 8 – Sep 8 |
| Kale | Sow outdoors (spring) | Apr 16 – May 6 |
| Kale | Sow outdoors (fall) | Jul 1 – Aug 8 |
| Carrots | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Carrots | Sow outdoors (fall) | Jun 8 – Jul 24 |
| Garlic | Plant outdoors (fall) | Oct 8 – Nov 8 |
Where these dates come from
ZIP code 18351 is matched to the NOAA station Belvidere Brg, NJ, 10.3 km away, at 263 ft elevation (26 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Belvidere Brg, NJ (used) | 263 ft | Apr 30 | Oct 18 |
| E Stroudsburg, PA | 471 ft | May 1 | Oct 12 |
| Phillipsburg-Easton Brg, NJ | 232 ft | Apr 18 | Oct 25 |
| Andover Aeroflex Ap, NJ | 583 ft | Apr 25 | Oct 19 |
Frost dates near Portland
- Mount Bethel, PA 18343 · last May 1, first Oct 12
- Columbia, NJ 07832 · last May 1, first Oct 12
- Delaware, NJ 07833 · last Apr 30, first Oct 18
- Delaware Water Gap, PA 18327 · last May 1, first Oct 12
- Minisink Hills, PA 18341 · last May 1, first Oct 12
- Hope, NJ 07844 · last Apr 25, first Oct 19
- Bangor, PA 18013 · last Apr 30, first Oct 18
- Shawnee On Delaware, PA 18356 · last May 1, first Oct 12
Frequently asked questions
- When is the last frost in Portland, PA?
- For ZIP code 18351, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Belvidere Brg, NJ weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Portland, PA?
- The average first fall frost (32°F) is October 18. There is a 1-in-10 chance of frost by October 3, so tender plants are at risk from that point on.
- How long is the growing season in 18351?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 168 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.