Frost dates for 17585Witmer, PA
The average last spring frost in Witmer is April 18 and the average first fall frost is October 25, giving a typical growing season of about 186 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Oct 25
- Growing season
- 186 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 10 (1-in-10 risk)
Last frost typically in 166 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 18 · May 1 · May 16 | Oct 2 · Oct 14 · Oct 27 | 165 days | 100% |
| Frost / freeze (32°F) | Apr 4 · Apr 18 · May 5 | Oct 10 · Oct 25 · Nov 6 | 186 days | 100% |
| Hard freeze (28°F) | Mar 21 · Apr 4 · Apr 18 | Oct 23 · Nov 5 · Nov 20 | 214 days | 100% |
Planting calendar for Witmer
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 5 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 15 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 7 |
| Sweet corn | Sow outdoors | May 4 – Jul 5 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jun 25 – Jul 5 |
| Broccoli | Transplant outdoors (fall) | Jul 25 – Aug 5 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 15 – Jul 15 |
| Cabbage | Transplant outdoors (fall) | Jul 15 – Aug 15 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 15 – Aug 31 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 1 – Sep 5 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 15 – Sep 15 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 8 – Aug 15 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 15 – Jul 31 |
| Garlic | Plant outdoors (fall) | Oct 15 – Nov 15 |
Where these dates come from
ZIP code 17585 is matched to the NOAA station Lancaster Ap, PA, 10.7 km away, at 403 ft elevation (1 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lancaster Ap, PA (used) | 403 ft | Apr 18 | Oct 25 |
| Lancaster 2Ne Fltr Plt, PA | 270 ft | Apr 19 | Oct 24 |
| New Holland 2 Se, PA | 605 ft | Apr 14 | Nov 1 |
| Landisville 2 Nw, PA | 360 ft | Apr 30 | Oct 10 |
Frost dates near Witmer
- Smoketown, PA 17576 · last Apr 19, first Oct 24
- Bird In Hand, PA 17505 · last Apr 19, first Oct 24
- Ronks, PA 17573 · last Apr 19, first Oct 24
- Leola, PA 17540 · last Apr 18, first Oct 25
- Lancaster, PA 17602 · last Apr 19, first Oct 24
- Lampeter, PA 17537 · last Apr 19, first Oct 24
- Talmage, PA 17580 · last Apr 18, first Oct 25
- Bart, PA 17503 · last Apr 19, first Oct 24
Frequently asked questions
- When is the last frost in Witmer, PA?
- For ZIP code 17585, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Lancaster Ap, PA weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Witmer, PA?
- The average first fall frost (32°F) is October 25. There is a 1-in-10 chance of frost by October 10, so tender plants are at risk from that point on.
- How long is the growing season in 17585?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 186 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.