Frost dates for 17801Sunbury, PA
The average last spring frost in Sunbury is April 30 and the average first fall frost is October 13, giving a typical growing season of about 166 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 30
- Average first fall frost
- Oct 13
- Growing season
- 166 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 30 (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 24 · May 11 · May 26 | Sep 20 · Oct 1 · Oct 15 | 143 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 30 · May 19 | Sep 30 · Oct 13 · Oct 31 | 166 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 14 · May 4 | Oct 10 · Oct 26 · Nov 10 | 193 days | 100% |
Planting calendar for Sunbury
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 23 |
| 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 3 |
| Summer squash | Sow outdoors | May 16 – Jun 30 |
| Winter squash & pumpkins | Sow outdoors | May 30 – Jun 30 |
| Snap beans | Sow outdoors | May 16 – Jul 26 |
| Sweet corn | Sow outdoors | May 16 – Jun 23 |
| 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 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Mar 2 – Mar 30 |
| Cabbage | Transplant outdoors (spring) | Mar 30 – Apr 30 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 30 – Jun 15 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 23 – May 6 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 30 – May 20 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 16 – May 6 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 17801 is matched to the NOAA station Sunbury, PA, 1 km away, at 575 ft elevation (129 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sunbury, PA (used) | 575 ft | Apr 30 | Oct 13 |
| Selinsgrove Penn Vly Ap, PA | 444 ft | Apr 27 | Oct 16 |
| Selinsgrove 2 S, PA | 420 ft | Apr 25 | Oct 22 |
| Lewisburg, PA | 500 ft | Apr 26 | Oct 20 |
Frost dates near Sunbury
- Shamokin Dam, PA 17876 · last Apr 27, first Oct 16
- Hummels Wharf, PA 17831 · last Apr 27, first Oct 16
- Northumberland, PA 17857 · last Apr 30, first Oct 13
- Selinsgrove, PA 17870 · last Apr 27, first Oct 16
- Winfield, PA 17889 · last Apr 30, first Oct 13
- Snydertown, PA 17877 · last Apr 30, first Oct 13
- Dornsife, PA 17823 · last Apr 30, first Oct 13
- Paxinos, PA 17860 · last Apr 30, first Oct 13
Frequently asked questions
- When is the last frost in Sunbury, PA?
- For ZIP code 17801, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Sunbury, PA weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Sunbury, PA?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 30, so tender plants are at risk from that point on.
- How long is the growing season in 17801?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 166 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.