Frost dates for 17013Carlisle, PA
The average last spring frost in Carlisle is April 23 and the average first fall frost is October 18, giving a typical growing season of about 177 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 23
- Average first fall frost
- Oct 18
- Growing season
- 177 days
Safer after May 9 (1-in-10 risk)
Possible by Oct 4 (1-in-10 risk)
Last frost typically in 171 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 20 · May 3 · May 19 | Sep 25 · Oct 6 · Oct 21 | 155 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 23 · May 9 | Oct 4 · Oct 18 · Nov 2 | 177 days | 100% |
| Hard freeze (28°F) | Mar 28 · Apr 10 · Apr 24 | Oct 14 · Nov 1 · Nov 14 | 202 days | 100% |
Planting calendar for Carlisle
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 23 – May 29 |
| Tomatoes | Transplant outdoors | May 9 – Jun 28 |
| Peppers | Start seeds indoors | Mar 23 – Apr 23 |
| Peppers | Transplant outdoors | May 23 – Jun 23 |
| Eggplant | Start seeds indoors | Apr 9 – May 8 |
| Eggplant | Transplant outdoors | May 23 – Jun 23 |
| Cucumbers | Sow outdoors | May 23 – Jul 8 |
| Summer squash | Sow outdoors | May 9 – Jun 23 |
| Winter squash & pumpkins | Sow outdoors | May 23 – Jun 23 |
| Snap beans | Sow outdoors | May 9 – Jul 31 |
| Sweet corn | Sow outdoors | May 9 – Jun 28 |
| Watermelon & cantaloupe | Sow outdoors | May 23 – Jun 23 |
| Okra | Sow outdoors | May 16 – Jun 8 |
| Peas | Sow outdoors (spring) | Mar 23 – May 8 |
| Potatoes | Plant outdoors (spring) | Mar 23 – May 23 |
| Onions | Start seeds indoors (spring) | Feb 9 – Mar 8 |
| Onions | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (spring) | Mar 5 – Apr 8 |
| Broccoli | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (fall) | Jun 18 – Jun 28 |
| Broccoli | Transplant outdoors (fall) | Jul 18 – Jul 29 |
| Cabbage | Start seeds indoors (spring) | Feb 23 – Mar 23 |
| Cabbage | Transplant outdoors (spring) | Mar 23 – Apr 23 |
| Cabbage | Start seeds indoors (fall) | Jun 8 – Jul 8 |
| Cabbage | Transplant outdoors (fall) | Jul 8 – Aug 8 |
| Leaf lettuce | Sow outdoors (spring) | Mar 23 – Jun 8 |
| Leaf lettuce | Sow outdoors (fall) | Jul 8 – Aug 24 |
| Spinach | Sow outdoors (spring) | Mar 16 – Apr 29 |
| Spinach | Sow outdoors (fall) | Jul 25 – Aug 29 |
| Radishes | Sow outdoors (spring) | Mar 23 – May 13 |
| Radishes | Sow outdoors (fall) | Jul 8 – Sep 8 |
| Kale | Sow outdoors (spring) | Apr 9 – Apr 29 |
| Kale | Sow outdoors (fall) | Jul 1 – Aug 8 |
| Carrots | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Carrots | Sow outdoors (fall) | Jun 8 – Jul 24 |
| Garlic | Plant outdoors (fall) | Oct 8 – Nov 8 |
Where these dates come from
ZIP code 17013 is matched to the NOAA station Carlisle Wtp, PA, 1.9 km away, at 430 ft elevation (17 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Carlisle Wtp, PA (used) | 430 ft | Apr 23 | Oct 18 |
| Bloserville 1 N, PA | 700 ft | Apr 18 | Oct 26 |
| Harrisburg 1 Ne, PA | 420 ft | Apr 15 | Oct 23 |
| Harrisburg Cptl Cy Ap, PA | 340 ft | Apr 9 | Nov 1 |
Frost dates near Carlisle
- Carlisle, PA 17015 · last Apr 23, first Oct 18
- Plainfield, PA 17081 · last Apr 23, first Oct 18
- Shermans Dale, PA 17090 · last Apr 23, first Oct 18
- New Kingstown, PA 17072 · last Apr 15, first Oct 23
- Boiling Springs, PA 17007 · last Apr 23, first Oct 18
- Landisburg, PA 17040 · last Apr 18, first Oct 26
- Mount Holly Springs, PA 17065 · last Apr 15, first Oct 27
- Mechanicsburg, PA 17050 · last Apr 15, first Oct 23
Frequently asked questions
- When is the last frost in Carlisle, PA?
- For ZIP code 17013, the average last spring frost (32°F) is April 23, based on NOAA 1991-2020 climate normals for the Carlisle Wtp, PA weather station. There is a 1-in-10 chance of a frost after May 9.
- When is the first frost in Carlisle, PA?
- The average first fall frost (32°F) is October 18. 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 17013?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 177 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.