Frost dates for 15139Oakmont, PA
The average last spring frost in Oakmont is April 16 and the average first fall frost is November 1, giving a typical growing season of about 197 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 16
- Average first fall frost
- Nov 1
- Growing season
- 197 days
Safer after May 4 (1-in-10 risk)
Possible by Oct 18 (1-in-10 risk)
Last frost typically in 164 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 13 · Apr 29 · May 17 | Oct 7 · Oct 20 · Nov 1 | 172 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 16 · May 4 | Oct 18 · Nov 1 · Nov 13 | 197 days | 100% |
| Hard freeze (28°F) | Mar 19 · Apr 3 · Apr 19 | Nov 1 · Nov 11 · Nov 25 | 222 days | 100% |
Planting calendar for Oakmont
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 16 – May 22 |
| Tomatoes | Transplant outdoors | May 2 – Jul 12 |
| Peppers | Start seeds indoors | Mar 16 – Apr 16 |
| Peppers | Transplant outdoors | May 16 – Jun 16 |
| Eggplant | Start seeds indoors | Apr 2 – May 1 |
| Eggplant | Transplant outdoors | May 16 – Jun 16 |
| Cucumbers | Sow outdoors | May 16 – Jul 22 |
| Summer squash | Sow outdoors | May 2 – Jun 16 |
| Winter squash & pumpkins | Sow outdoors | May 16 – Jun 16 |
| Snap beans | Sow outdoors | May 2 – Aug 14 |
| Sweet corn | Sow outdoors | May 2 – Jul 12 |
| Watermelon & cantaloupe | Sow outdoors | May 16 – Jun 16 |
| Okra | Sow outdoors | May 9 – Jun 1 |
| Peas | Sow outdoors (spring) | Mar 16 – May 1 |
| Potatoes | Plant outdoors (spring) | Mar 16 – May 16 |
| Onions | Start seeds indoors (spring) | Feb 2 – Mar 1 |
| Onions | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (spring) | Feb 26 – Apr 1 |
| Broccoli | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (fall) | Jul 2 – Jul 12 |
| Broccoli | Transplant outdoors (fall) | Aug 1 – Aug 12 |
| Cabbage | Start seeds indoors (spring) | Feb 16 – Mar 16 |
| Cabbage | Transplant outdoors (spring) | Mar 16 – Apr 16 |
| Cabbage | Start seeds indoors (fall) | Jun 22 – Jul 22 |
| Cabbage | Transplant outdoors (fall) | Jul 22 – Aug 22 |
| Leaf lettuce | Sow outdoors (spring) | Mar 16 – Jun 1 |
| Leaf lettuce | Sow outdoors (fall) | Jul 22 – Sep 7 |
| Spinach | Sow outdoors (spring) | Mar 9 – Apr 22 |
| Spinach | Sow outdoors (fall) | Aug 8 – Sep 12 |
| Radishes | Sow outdoors (spring) | Mar 16 – May 6 |
| Radishes | Sow outdoors (fall) | Jul 22 – Sep 22 |
| Kale | Sow outdoors (spring) | Apr 2 – Apr 22 |
| Kale | Sow outdoors (fall) | Jul 15 – Aug 22 |
| Carrots | Sow outdoors (spring) | Apr 16 – Jun 1 |
| Carrots | Sow outdoors (fall) | Jun 22 – Aug 7 |
| Garlic | Plant outdoors (fall) | Oct 22 – Nov 22 |
Where these dates come from
ZIP code 15139 is matched to the NOAA station Acmetonia Lock 3, PA, 2.6 km away, at 748 ft elevation (141 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Acmetonia Lock 3, PA (used) | 748 ft | Apr 16 | Nov 1 |
| Braddock Lock 2, PA | 730 ft | Apr 5 | Nov 10 |
| Natrona Lock 4, PA | 760 ft | Apr 16 | Nov 2 |
| Murrysville 2 Sw, PA | 860 ft | Apr 22 | Oct 25 |
Frost dates near Oakmont
- Verona, PA 15147 · last Apr 18, first Oct 28
- Pittsburgh, PA 15238 · last Apr 18, first Oct 28
- Harwick, PA 15049 · last Apr 16, first Nov 1
- Springdale, PA 15144 · last Apr 16, first Nov 1
- Cheswick, PA 15024 · last Apr 16, first Nov 1
- Indianola, PA 15051 · last Apr 16, first Nov 1
- Rural Ridge, PA 15075 · last Apr 16, first Nov 1
- New Kensington, PA 15069 · last Apr 16, first Nov 1
Frequently asked questions
- When is the last frost in Oakmont, PA?
- For ZIP code 15139, the average last spring frost (32°F) is April 16, based on NOAA 1991-2020 climate normals for the Acmetonia Lock 3, PA weather station. There is a 1-in-10 chance of a frost after May 4.
- When is the first frost in Oakmont, PA?
- The average first fall frost (32°F) is November 1. There is a 1-in-10 chance of frost by October 18, so tender plants are at risk from that point on.
- How long is the growing season in 15139?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 197 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.