Frost dates for 15547Jennerstown, PA
The average last spring frost in Jennerstown is April 30 and the average first fall frost is October 17, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 30
- Average first fall frost
- Oct 17
- Growing season
- 170 days
Safer after May 18 (1-in-10 risk)
Possible by Oct 3 (1-in-10 risk)
Last frost typically in 179 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 25 · May 11 · May 29 | Sep 23 · Oct 6 · Oct 19 | 147 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 30 · May 18 | Oct 3 · Oct 17 · Oct 31 | 170 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 17 · May 8 | Oct 13 · Oct 30 · Nov 13 | 195 days | 100% |
Planting calendar for Jennerstown
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 27 |
| 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 7 |
| Summer squash | Sow outdoors | May 16 – Jun 30 |
| Winter squash & pumpkins | Sow outdoors | May 30 – Jun 30 |
| Snap beans | Sow outdoors | May 16 – Jul 30 |
| Sweet corn | Sow outdoors | May 16 – Jun 27 |
| 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 17 – Jun 27 |
| Broccoli | Transplant outdoors (fall) | Jul 17 – Jul 28 |
| Cabbage | Start seeds indoors (spring) | Mar 2 – Mar 30 |
| Cabbage | Transplant outdoors (spring) | Mar 30 – Apr 30 |
| Cabbage | Start seeds indoors (fall) | Jun 7 – Jul 7 |
| Cabbage | Transplant outdoors (fall) | Jul 7 – Aug 7 |
| Leaf lettuce | Sow outdoors (spring) | Mar 30 – Jun 15 |
| Leaf lettuce | Sow outdoors (fall) | Jul 7 – Aug 23 |
| Spinach | Sow outdoors (spring) | Mar 23 – May 6 |
| Spinach | Sow outdoors (fall) | Jul 24 – Aug 28 |
| Radishes | Sow outdoors (spring) | Mar 30 – May 20 |
| Radishes | Sow outdoors (fall) | Jul 7 – Sep 7 |
| Kale | Sow outdoors (spring) | Apr 16 – May 6 |
| Kale | Sow outdoors (fall) | Jun 30 – Aug 7 |
| Carrots | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Carrots | Sow outdoors (fall) | Jun 7 – Jul 23 |
| Garlic | Plant outdoors (fall) | Oct 7 – Nov 7 |
Where these dates come from
ZIP code 15547 is matched to the NOAA station Donegal 2 Nw, PA, 29.5 km away, at 1,800 ft elevation (152 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Donegal 2 Nw, PA (used) | 1,800 ft | Apr 30 | Oct 17 |
| Laurel Summit, PA | 2,730 ft | May 6 | Oct 12 |
| Laurel Mtn, PA | 2,760 ft | Apr 26 | Oct 17 |
| Rector 3 Ssw, PA | 1,330 ft | May 5 | Oct 6 |
Frost dates near Jennerstown
- Jenners, PA 15546 · last Apr 30, first Oct 17
- Gray, PA 15544 · last Apr 30, first Oct 17
- Boswell, PA 15531 · last Apr 30, first Oct 17
- Acosta, PA 15520 · last Apr 30, first Oct 17
- Sipesville, PA 15561 · last May 6, first Oct 12
- Quecreek, PA 15555 · last Apr 30, first Oct 17
- Jerome, PA 15937 · last Apr 30, first Oct 17
- Stoystown, PA 15563 · last May 12, first Oct 5
Frequently asked questions
- When is the last frost in Jennerstown, PA?
- For ZIP code 15547, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Donegal 2 Nw, PA weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Jennerstown, PA?
- The average first fall frost (32°F) is October 17. There is a 1-in-10 chance of frost by October 3, so tender plants are at risk from that point on.
- How long is the growing season in 15547?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 170 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.