Frost dates for 17878Stillwater, PA
The average last spring frost in Stillwater is May 4 and the average first fall frost is October 11, giving a typical growing season of about 159 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 4
- Average first fall frost
- Oct 11
- Growing season
- 159 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 29 (1-in-10 risk)
Last frost typically in 182 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 30 · May 15 · May 31 | Sep 20 · Oct 1 · Oct 12 | 138 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 4 · May 19 | Sep 29 · Oct 11 · Oct 27 | 159 days | 100% |
| Hard freeze (28°F) | Apr 8 · Apr 22 · May 10 | Oct 8 · Oct 24 · Nov 9 | 184 days | 100% |
Planting calendar for Stillwater
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 | Apr 3 – Jun 9 |
| Tomatoes | Transplant outdoors | May 20 – Jun 21 |
| Peppers | Start seeds indoors | Apr 3 – May 4 |
| Peppers | Transplant outdoors | Jun 3 – Jul 4 |
| Eggplant | Start seeds indoors | Apr 20 – May 19 |
| Eggplant | Transplant outdoors | Jun 3 – Jul 4 |
| Cucumbers | Sow outdoors | Jun 3 – Jul 1 |
| Summer squash | Sow outdoors | May 20 – Jul 4 |
| Winter squash & pumpkins | Sow outdoors | Jun 3 – Jul 4 |
| Snap beans | Sow outdoors | May 20 – Jul 24 |
| Sweet corn | Sow outdoors | May 20 – Jun 21 |
| Watermelon & cantaloupe | Sow outdoors | Jun 3 – Jul 4 |
| Okra | Sow outdoors | May 27 – Jun 19 |
| Peas | Sow outdoors (spring) | Apr 3 – May 19 |
| Potatoes | Plant outdoors (spring) | Apr 3 – Jun 3 |
| Onions | Start seeds indoors (spring) | Feb 20 – Mar 19 |
| Onions | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (spring) | Mar 16 – Apr 19 |
| Broccoli | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (fall) | Jun 11 – Jun 21 |
| Broccoli | Transplant outdoors (fall) | Jul 11 – Jul 22 |
| Cabbage | Start seeds indoors (spring) | Mar 6 – Apr 3 |
| Cabbage | Transplant outdoors (spring) | Apr 3 – May 4 |
| Cabbage | Start seeds indoors (fall) | Jun 1 – Jul 1 |
| Cabbage | Transplant outdoors (fall) | Jul 1 – Aug 1 |
| Leaf lettuce | Sow outdoors (spring) | Apr 3 – Jun 19 |
| Leaf lettuce | Sow outdoors (fall) | Jul 1 – Aug 17 |
| Spinach | Sow outdoors (spring) | Mar 27 – May 10 |
| Spinach | Sow outdoors (fall) | Jul 18 – Aug 22 |
| Radishes | Sow outdoors (spring) | Apr 3 – May 24 |
| Radishes | Sow outdoors (fall) | Jul 1 – Sep 1 |
| Kale | Sow outdoors (spring) | Apr 20 – May 10 |
| Kale | Sow outdoors (fall) | Jun 24 – Aug 1 |
| Carrots | Sow outdoors (spring) | May 4 – Jun 19 |
| Carrots | Sow outdoors (fall) | Jun 1 – Jul 17 |
| Garlic | Plant outdoors (fall) | Oct 1 – Nov 1 |
Where these dates come from
ZIP code 17878 is matched to the NOAA station Benton 3 Ne, PA, 9.3 km away, at 1,095 ft elevation (308 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Benton 3 Ne, PA (used) | 1,095 ft | May 4 | Oct 11 |
| Laporte, PA | 1,966 ft | May 6 | Oct 7 |
| Bear Gap, PA | 1,015 ft | Apr 27 | Oct 20 |
| Mahanoy City 2 N, PA | 1,710 ft | Apr 30 | Oct 22 |
Frost dates near Stillwater
- Orangeville, PA 17859 · last Apr 30, first Oct 13
- Cambra, PA 18611 · last May 4, first Oct 11
- Benton, PA 17814 · last May 4, first Oct 11
- Huntington Mills, PA 18622 · last May 4, first Oct 11
- Millville, PA 17846 · last Apr 30, first Oct 13
- Berwick, PA 18603 · last Apr 30, first Oct 13
- Mifflinville, PA 18631 · last Apr 30, first Oct 13
- Unityville, PA 17774 · last May 4, first Oct 11
Frequently asked questions
- When is the last frost in Stillwater, PA?
- For ZIP code 17878, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the Benton 3 Ne, PA weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Stillwater, PA?
- The average first fall frost (32°F) is October 11. There is a 1-in-10 chance of frost by September 29, so tender plants are at risk from that point on.
- How long is the growing season in 17878?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 159 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.