Frost dates for 17763Ralston, PA
The average last spring frost in Ralston is May 16 and the average first fall frost is October 2, giving a typical growing season of about 139 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Oct 2
- Growing season
- 139 days
Safer after May 29 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 194 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) | May 12 · May 29 · Jun 11 | Sep 7 · Sep 22 · Oct 4 | 115 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 16 · May 29 | Sep 18 · Oct 2 · Oct 16 | 139 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 1 · May 19 | Sep 29 · Oct 13 · Oct 31 | 163 days | 100% |
Planting calendar for Ralston
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 12 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 22 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 15 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | Jun 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 17763 is matched to the NOAA station Canton, PA, 18.9 km away, at 1,140 ft elevation (87 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Canton, PA (used) | 1,140 ft | May 16 | Oct 2 |
| Williamsport 2, PA | 525 ft | Apr 25 | Oct 24 |
| Williamsport, PA | 520 ft | Apr 24 | Oct 23 |
| Laporte, PA | 1,966 ft | May 6 | Oct 7 |
Frost dates near Ralston
- Roaring Branch, PA 17765 · last May 16, first Oct 2
- Trout Run, PA 17771 · last May 6, first Oct 7
- Grover, PA 17735 · last May 16, first Oct 2
- Liberty, PA 16930 · last May 10, first Oct 5
- Shunk, PA 17768 · last May 14, first Oct 2
- Canton, PA 17724 · last May 16, first Oct 2
- Williamsport, PA 17705 · last Apr 25, first Oct 24
- Morris Run, PA 16939 · last May 10, first Oct 5
Frequently asked questions
- When is the last frost in Ralston, PA?
- For ZIP code 17763, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Canton, PA weather station. There is a 1-in-10 chance of a frost after May 29.
- When is the first frost in Ralston, PA?
- The average first fall frost (32°F) is October 2. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 17763?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 139 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.