Frost dates for Pittsburgh Intl Airport, PA
At Pittsburgh Intl Airport, the median last spring frost (32°F) is Apr 23 and the median first fall frost is Oct 23, for a typical growing season of 181 days. For a 90% chance that the last frost has passed, wait until May 12. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 23Last spring frost (median)50% chance of 32°F after this date
- May 12Safer planting date10% chance of 32°F after this date
- Oct 23First fall frost (median)50% chance of 32°F by this date
- 181 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 19 | May 4 | May 22 |
| 32°F | Apr 9 | Apr 23 | May 12 |
| 28°F | Mar 28 | Apr 12 | Apr 27 |
| 24°F | Mar 15 | Mar 31 | Apr 14 |
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 30 | Oct 12 | Oct 25 |
| 32°F | Oct 9 | Oct 23 | Nov 6 |
| 28°F | Oct 21 | Nov 4 | Nov 18 |
| 24°F | Nov 1 | Nov 14 | 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 | 138 days | 159 days | 178 days |
| 32°F | 160 days | 181 days | 202 days |
| 28°F | 186 days | 207 days | 227 days |
| 24°F | 208 days | 228 days | 251 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 |
|---|---|---|---|
| 15108 | 6b | -5 to 0°F | 2 km |
| 15126 | 6b | -5 to 0°F | 7 km |
| 15071 | 6b | -5 to 0°F | 8 km |
| 15082 | 6b | -5 to 0°F | 12 km |
| 15019 | 6b | -5 to 0°F | 13 km |
| 15142 | 6b | -5 to 0°F | 14 km |
| 15060 | 6b | -5 to 0°F | 14 km |
| 15057 | 6b | -5 to 0°F | 14 km |
| 15064 | 6b | -5 to 0°F | 15 km |
| 15017 | 6b | -5 to 0°F | 17 km |
| 15361 | 6b | -5 to 0°F | 17 km |
| 15078 | 6b | -5 to 0°F | 20 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 USW00094823, at 40.4847, -80.2144, elevation 367 m (1,203 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 114.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Moon Twp (5 km)
- Glenwillard Dashields L&d (7 km)
- Emsworth L/d Ohio River (11 km)
- Montgomery L&d (23 km)
- Pittsburgh Allegheny Co Airport (29 km)
- Braddock Lock 2 (32 km)
- Beaver Falls 1 NE (32 km)
- McKeesport (34 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.