Frost dates for McKeesport, PA
At McKeesport, the median last spring frost (32°F) is May 2 and the median first fall frost is Oct 20, for a typical growing season of 170 days. For a 90% chance that the last frost has passed, wait until May 20. Nearby ZIP codes are in USDA hardiness zone 6b.
- May 2Last spring frost (median)50% chance of 32°F after this date
- May 20Safer planting date10% chance of 32°F after this date
- Oct 20First fall frost (median)50% chance of 32°F by this date
- 170 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 26 | May 12 | May 27 |
| 32°F | Apr 17 | May 2 | May 20 |
| 28°F | Apr 2 | Apr 20 | May 10 |
| 24°F | Mar 18 | Apr 4 | Apr 30 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 21 | Oct 7 | Oct 24 |
| 32°F | Oct 1 | Oct 20 | Nov 3 |
| 28°F | Oct 10 | Nov 1 | Nov 14 |
| 24°F | Oct 28 | Nov 12 | Dec 1 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 128 days | 149 days | 171 days |
| 32°F | 144 days | 170 days | 192 days |
| 28°F | 167 days | 194 days | 217 days |
| 24°F | 194 days | 222 days | 246 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 15132 | 6b | -5 to 0°F | 1 km |
| 15133 | 6b | -5 to 0°F | 1 km |
| 15045 | 6b | -5 to 0°F | 3 km |
| 15131 | 6b | -5 to 0°F | 5 km |
| 15135 | 6b | -5 to 0°F | 6 km |
| 15028 | 6b | -5 to 0°F | 7 km |
| 15088 | 6b | -5 to 0°F | 8 km |
| 15018 | 6b | -5 to 0°F | 8 km |
| 15037 | 6b | -5 to 0°F | 9 km |
| 15083 | 6b | -5 to 0°F | 11 km |
| 15678 | 6b | -5 to 0°F | 13 km |
| 15637 | 6b | -5 to 0°F | 15 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00365573, at 40.3392, -79.8603, elevation 226 m (740 ft).
- Data quality: Standard (24+ years of data), 25 years of freeze data.
- Average days per year at or below 32°F: 124.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Pittsburgh Allegheny Co Airport (5 km)
- Braddock Lock 2 (6 km)
- Murrysville 2 SW (14 km)
- Donora 1 SW (20 km)
- Charleroi Lock 4 (22 km)
- Acmetonia Lock 3 (22 km)
- Emsworth L/d Ohio River (27 km)
- Salina 3 W (33 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.