Frost dates in Pittsburgh, Pennsylvania
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in Pittsburgh is April 18, and the average first fall frost is October 28, from NOAA's Pittsburgh Allegheny Co Airport station, 7 miles from the middle of Pittsburgh. 1 year in 10 the last frost comes after May 6, and the first one by October 14. That leaves about 193 frost-free days. Pittsburgh is in USDA planting zone 6b.
Weather stations around Pittsburgh
The first row is the date most people in Pittsburgh go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| Pittsburgh Allegheny Co Airport 7 mi away, 1,248 ft | April 18 1 in 10 after May 6 | October 28 1 in 10 by October 14 | 193 days |
| Braddock Lock 2 7 mi away, 730 ft | April 5 1 in 10 after April 22 | November 10 1 in 10 by October 28 | 219 days |
| Emsworth L/D Ohio Rvr 7 mi away, 717 ft | April 24 1 in 10 after May 11 | October 27 1 in 10 by October 13 | 186 days |
| Mckeesport 9 mi away, 740 ft | May 2 1 in 10 after May 20 | October 20 1 in 10 by October 1 | 171 days |
| Acmetonia Lock 3 11 mi away, 748 ft | April 16 1 in 10 after May 4 | November 1 1 in 10 by October 18 | 199 days |
Distances are from the middle of Pittsburgh as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 15219, at the middle of the city.
Your exact ZIP code
Pittsburgh covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of Pennsylvania, station by station.
Other Pennsylvania cities: Philadelphia
Nearby: Akron, OH · Cleveland, OH · Columbus, OH
Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer