Frost dates for 15101Allison Park, PA
The average last spring frost in Allison Park is April 24 and the average first fall frost is October 27, giving a typical growing season of about 186 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 24
- Average first fall frost
- Oct 27
- Growing season
- 186 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 13 (1-in-10 risk)
Last frost typically in 172 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 5 · May 21 | Oct 2 · Oct 16 · Oct 28 | 163 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 24 · May 11 | Oct 13 · Oct 27 · Nov 7 | 186 days | 100% |
| Hard freeze (28°F) | Mar 28 · Apr 12 · Apr 26 | Oct 24 · Nov 5 · Nov 20 | 209 days | 100% |
Planting calendar for Allison Park
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 24 – May 30 |
| Tomatoes | Transplant outdoors | May 10 – Jul 7 |
| Peppers | Start seeds indoors | Mar 24 – Apr 24 |
| Peppers | Transplant outdoors | May 24 – Jun 24 |
| Eggplant | Start seeds indoors | Apr 10 – May 9 |
| Eggplant | Transplant outdoors | May 24 – Jun 24 |
| Cucumbers | Sow outdoors | May 24 – Jul 17 |
| Summer squash | Sow outdoors | May 10 – Jun 24 |
| Winter squash & pumpkins | Sow outdoors | May 24 – Jun 24 |
| Snap beans | Sow outdoors | May 10 – Aug 9 |
| Sweet corn | Sow outdoors | May 10 – Jul 7 |
| Watermelon & cantaloupe | Sow outdoors | May 24 – Jun 24 |
| Okra | Sow outdoors | May 17 – Jun 9 |
| Peas | Sow outdoors (spring) | Mar 24 – May 9 |
| Potatoes | Plant outdoors (spring) | Mar 24 – May 24 |
| Onions | Start seeds indoors (spring) | Feb 10 – Mar 9 |
| Onions | Transplant outdoors (spring) | Apr 10 – May 9 |
| Broccoli | Start seeds indoors (spring) | Mar 6 – Apr 9 |
| Broccoli | Transplant outdoors (spring) | Apr 10 – May 9 |
| Broccoli | Start seeds indoors (fall) | Jun 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 24 – Mar 24 |
| Cabbage | Transplant outdoors (spring) | Mar 24 – Apr 24 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 24 – Jun 9 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 17 – Apr 30 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 24 – May 14 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Apr 10 – Apr 30 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 24 – Jun 9 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 15101 is matched to the NOAA station Emsworth L/D Ohio Rvr, PA, 12.7 km away, at 717 ft elevation (320 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Emsworth L/D Ohio Rvr, PA (used) | 717 ft | Apr 24 | Oct 27 |
| Acmetonia Lock 3, PA | 748 ft | Apr 16 | Nov 1 |
| Glenwillard Dashields L&D, PA | 710 ft | Apr 8 | Nov 8 |
| Natrona Lock 4, PA | 760 ft | Apr 16 | Nov 2 |
Frost dates near Allison Park
- Wildwood, PA 15091 · last Apr 24, first Oct 27
- Glenshaw, PA 15116 · last Apr 24, first Oct 27
- Gibsonia, PA 15044 · last May 7, first Oct 14
- Pittsburgh, PA 15237 · last Apr 23, first Oct 23
- Ingomar, PA 15127 · last Apr 23, first Oct 23
- Indianola, PA 15051 · last Apr 16, first Nov 1
- Bakerstown, PA 15007 · last May 7, first Oct 14
- Wexford, PA 15090 · last Apr 23, first Oct 23
Frequently asked questions
- When is the last frost in Allison Park, PA?
- For ZIP code 15101, the average last spring frost (32°F) is April 24, based on NOAA 1991-2020 climate normals for the Emsworth L/D Ohio Rvr, PA weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Allison Park, PA?
- The average first fall frost (32°F) is October 27. There is a 1-in-10 chance of frost by October 13, so tender plants are at risk from that point on.
- How long is the growing season in 15101?
- 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.