Frost dates for Johnstown Cambria Co Airport, PA
At Johnstown Cambria Co Airport, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 21, for a typical growing season of 176 days. For a 90% chance that the last frost has passed, wait until May 17. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- Apr 29Last spring frost (median)50% chance of 32°F after this date
- May 17Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 176 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 22 | May 8 | May 24 |
| 32°F | Apr 14 | Apr 29 | May 17 |
| 28°F | Apr 1 | Apr 17 | May 5 |
| 24°F | Mar 20 | Apr 4 | Apr 20 |
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 24 | Oct 8 | Oct 23 |
| 32°F | Oct 5 | Oct 21 | Nov 5 |
| 28°F | Oct 19 | Nov 2 | Nov 16 |
| 24°F | Nov 1 | Nov 12 | Nov 29 |
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 | 131 days | 152 days | 173 days |
| 32°F | 153 days | 176 days | 197 days |
| 28°F | 177 days | 200 days | 220 days |
| 24°F | 203 days | 221 days | 243 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 |
|---|---|---|---|
| 15904 | 6b | -5 to 0°F | 1 km |
| 15902 | 6b | -5 to 0°F | 3 km |
| 15956 | 6a | -10 to -5°F | 5 km |
| 15952 | 6a | -10 to -5°F | 5 km |
| 15945 | 6b | -5 to 0°F | 6 km |
| 15951 | 6a | -10 to -5°F | 6 km |
| 15901 | 6b | -5 to 0°F | 7 km |
| 15942 | 6a | -10 to -5°F | 9 km |
| 15930 | 6b | -5 to 0°F | 10 km |
| 15909 | 6b | -5 to 0°F | 11 km |
| 15928 | 6a | -10 to -5°F | 11 km |
| 15906 | 6b | -5 to 0°F | 11 km |
| 15963 | 6a | -10 to -5°F | 11 km |
| 15921 | 6a | -10 to -5°F | 12 km |
| 15905 | 6a | -10 to -5°F | 12 km |
| 15955 | 6b | -5 to 0°F | 12 km |
| 15953 | 6a | -10 to -5°F | 13 km |
| 15936 | 6a | -10 to -5°F | 18 km |
| 15954 | 6b | -5 to 0°F | 18 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 USW00004726, at 40.3161, -78.8339, elevation 696 m (2,284 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 127.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ebensburg Sewage Plant (19 km)
- Laurel Summit (31 km)
- Laurel Mountain (33 km)
- Shawnee State Park (36 km)
- Altoona 7 SW (37 km)
- Altoona 3 W (37 km)
- Indiana 3 SE (39 km)
- Rector 3 SSW (40 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.