Frost dates for 15133Mckeesport, PA
The average last spring frost in Mckeesport 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 Mckeesport
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 15133 is matched to the NOAA station Mckeesport, PA, 1 km away, at 740 ft elevation (18 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 |
| Murrysville 2 Sw, PA | 860 ft | Apr 22 | Oct 25 |
Frost dates near Mckeesport
- Mckeesport, PA 15131 · last May 2, first Oct 20
- West Mifflin, PA 15122 · last Apr 18, first Oct 28
- Dravosburg, PA 15034 · last May 2, first Oct 20
- Duquesne, PA 15110 · last May 2, first Oct 20
- Glassport, PA 15045 · last May 2, first Oct 20
- North Versailles, PA 15137 · last Apr 18, first Oct 28
- Homestead, PA 15120 · last Apr 18, first Oct 28
- Braddock, PA 15104 · last May 2, first Oct 20
Frequently asked questions
- When is the last frost in Mckeesport, PA?
- For ZIP code 15133, 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 Mckeesport, 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 15133?
- 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.