Frost dates for 15289Pittsburgh, PA
The average last spring frost in Pittsburgh is May 2 and the average first fall frost is October 20, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 2
- Average first fall frost
- Oct 20
- Growing season
- 170 days
Safer after May 20 (1-in-10 risk)
Possible by Oct 1 (1-in-10 risk)
Last frost typically in 180 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 26 · May 12 · May 27 | Sep 21 · Oct 7 · Oct 24 | 149 days | 100% |
| Frost / freeze (32°F) | Apr 17 · May 2 · May 20 | Oct 1 · Oct 20 · Nov 3 | 170 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 20 · May 10 | Oct 10 · Nov 1 · Nov 14 | 194 days | 100% |
Planting calendar for Pittsburgh
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 | Apr 1 – Jun 7 |
| Tomatoes | Transplant outdoors | May 18 – Jun 30 |
| Peppers | Start seeds indoors | Apr 1 – May 2 |
| Peppers | Transplant outdoors | Jun 1 – Jul 2 |
| Eggplant | Start seeds indoors | Apr 18 – May 17 |
| Eggplant | Transplant outdoors | Jun 1 – Jul 2 |
| Cucumbers | Sow outdoors | Jun 1 – Jul 10 |
| Summer squash | Sow outdoors | May 18 – Jul 2 |
| Winter squash & pumpkins | Sow outdoors | Jun 1 – Jul 2 |
| Snap beans | Sow outdoors | May 18 – Aug 2 |
| Sweet corn | Sow outdoors | May 18 – Jun 30 |
| Watermelon & cantaloupe | Sow outdoors | Jun 1 – Jul 2 |
| Okra | Sow outdoors | May 25 – Jun 17 |
| Peas | Sow outdoors (spring) | Apr 1 – May 17 |
| Potatoes | Plant outdoors (spring) | Apr 1 – Jun 1 |
| Onions | Start seeds indoors (spring) | Feb 18 – Mar 17 |
| Onions | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (spring) | Mar 14 – Apr 17 |
| Broccoli | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (fall) | Jun 20 – Jun 30 |
| Broccoli | Transplant outdoors (fall) | Jul 20 – Jul 31 |
| Cabbage | Start seeds indoors (spring) | Mar 4 – Apr 1 |
| Cabbage | Transplant outdoors (spring) | Apr 1 – May 2 |
| Cabbage | Start seeds indoors (fall) | Jun 10 – Jul 10 |
| Cabbage | Transplant outdoors (fall) | Jul 10 – Aug 10 |
| Leaf lettuce | Sow outdoors (spring) | Apr 1 – Jun 17 |
| Leaf lettuce | Sow outdoors (fall) | Jul 10 – Aug 26 |
| Spinach | Sow outdoors (spring) | Mar 25 – May 8 |
| Spinach | Sow outdoors (fall) | Jul 27 – Aug 31 |
| Radishes | Sow outdoors (spring) | Apr 1 – May 22 |
| Radishes | Sow outdoors (fall) | Jul 10 – Sep 10 |
| Kale | Sow outdoors (spring) | Apr 18 – May 8 |
| Kale | Sow outdoors (fall) | Jul 3 – Aug 10 |
| Carrots | Sow outdoors (spring) | May 2 – Jun 17 |
| Carrots | Sow outdoors (fall) | Jun 10 – Jul 26 |
| Garlic | Plant outdoors (fall) | Oct 10 – Nov 10 |
Where these dates come from
ZIP code 15289 is matched to the NOAA station Mckeesport, PA, 13.7 km away, at 740 ft elevation (172 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mckeesport, PA (used) | 740 ft | May 2 | Oct 20 |
| Braddock Lock 2, PA | 730 ft | Apr 5 | Nov 10 |
| Pittsburgh Allegheny Co Ap, PA | 1,248 ft | Apr 18 | Oct 28 |
| Emsworth L/D Ohio Rvr, PA | 717 ft | Apr 24 | Oct 27 |
Frost dates near Pittsburgh
- Pittsburgh, PA 15260 · last May 2, first Oct 20
- Homestead, PA 15120 · last Apr 18, first Oct 28
- Coulters, PA 15028 · last Apr 18, first Oct 28
- West Mifflin, PA 15123 · last Apr 18, first Oct 28
- Braddock, PA 15104 · last May 2, first Oct 20
- East Pittsburgh, PA 15112 · last May 2, first Oct 20
- Glenshaw, PA 15116 · last Apr 24, first Oct 27
- Verona, PA 15147 · last Apr 18, first Oct 28
Frequently asked questions
- When is the last frost in Pittsburgh, PA?
- For ZIP code 15289, the average last spring frost (32°F) is May 2, based on NOAA 1991-2020 climate normals for the Mckeesport, PA weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Pittsburgh, PA?
- The average first fall frost (32°F) is October 20. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
- How long is the growing season in 15289?
- 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.