Frost dates for Acmetonia Lock 3, PA
At Acmetonia Lock 3, the median last spring frost (32°F) is Apr 16 and the median first fall frost is Nov 1, for a typical growing season of 197 days. For a 90% chance that the last frost has passed, wait until May 4. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 16Last spring frost (median)50% chance of 32°F after this date
- May 4Safer planting date10% chance of 32°F after this date
- Nov 1First fall frost (median)50% chance of 32°F by this date
- 197 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 13 | Apr 29 | May 17 |
| 32°F | Mar 31 | Apr 16 | May 4 |
| 28°F | Mar 19 | Apr 3 | Apr 19 |
| 24°F | Mar 8 | Mar 24 | Apr 6 |
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 | Oct 7 | Oct 20 | Nov 1 |
| 32°F | Oct 18 | Nov 1 | Nov 13 |
| 28°F | Nov 1 | Nov 11 | Nov 25 |
| 24°F | Nov 7 | Nov 20 | Dec 9 |
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 | 150 days | 172 days | 192 days |
| 32°F | 175 days | 197 days | 216 days |
| 28°F | 202 days | 222 days | 241 days |
| 24°F | 222 days | 242 days | 265 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 |
|---|---|---|---|
| 15139 | 6b | -5 to 0°F | 2 km |
| 15049 | 6b | -5 to 0°F | 2 km |
| 15144 | 6b | -5 to 0°F | 3 km |
| 15147 | 6b | -5 to 0°F | 5 km |
| 15051 | 6b | -5 to 0°F | 5 km |
| 15238 | 6b | -5 to 0°F | 5 km |
| 15075 | 6b | -5 to 0°F | 6 km |
| 15024 | 6b | -5 to 0°F | 6 km |
| 15076 | 6b | -5 to 0°F | 8 km |
| 15215 | 6b | -5 to 0°F | 9 km |
| 15116 | 6b | -5 to 0°F | 10 km |
| 15006 | 6b | -5 to 0°F | 12 km |
| 15201 | 7a | 0 to 5°F | 12 km |
| 15101 | 6b | -5 to 0°F | 13 km |
| 15044 | 6b | -5 to 0°F | 16 km |
| 15007 | 6b | -5 to 0°F | 16 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 USC00360022, at 40.5361, -79.8153, elevation 228 m (748 ft).
- Data quality: Estimated from nearby stations (2+ years), 8 years of freeze data.
- Average days per year at or below 32°F: 117.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Natrona Lock 4 (12 km)
- Murrysville 2 SW (16 km)
- Braddock Lock 2 (16 km)
- Schenley Lock 5 (21 km)
- Pittsburgh Allegheny Co Airport (22 km)
- McKeesport (22 km)
- Salina 3 W (23 km)
- Emsworth L/d Ohio River (23 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.