Frost dates for Altoona Blair Co Airport, PA
At Altoona Blair Co Airport, the median last spring frost (32°F) is Apr 23 and the median first fall frost is Oct 21, for a typical growing season of 177 days. For a 90% chance that the last frost has passed, wait until May 11. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 23Last spring frost (median)50% chance of 32°F after this date
- May 11Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 177 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 21 | May 4 | May 22 |
| 32°F | Apr 8 | Apr 23 | May 11 |
| 28°F | Mar 28 | Apr 11 | Apr 29 |
| 24°F | Mar 16 | 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 24 | Oct 7 | Oct 23 |
| 32°F | Oct 5 | Oct 21 | Nov 4 |
| 28°F | Oct 19 | Nov 1 | Nov 18 |
| 24°F | Oct 31 | 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 | 134 days | 155 days | 174 days |
| 32°F | 154 days | 177 days | 200 days |
| 28°F | 179 days | 203 days | 225 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 |
|---|---|---|---|
| 16662 | 6b | -5 to 0°F | 2 km |
| 16631 | 6b | -5 to 0°F | 4 km |
| 16673 | 6b | -5 to 0°F | 6 km |
| 16695 | 6b | -5 to 0°F | 10 km |
| 16678 | 6b | -5 to 0°F | 11 km |
| 16638 | 6b | -5 to 0°F | 11 km |
| 16672 | 6b | -5 to 0°F | 14 km |
| 16664 | 6b | -5 to 0°F | 16 km |
| 16634 | 6b | -5 to 0°F | 16 km |
| 16659 | 6b | -5 to 0°F | 16 km |
| 16670 | 6b | -5 to 0°F | 16 km |
| 16633 | 6b | -5 to 0°F | 17 km |
| 16625 | 6b | -5 to 0°F | 17 km |
| 16655 | 6b | -5 to 0°F | 17 km |
| 16679 | 6b | -5 to 0°F | 19 km |
| 16694 | 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 USW00014736, at 40.2964, -78.3203, elevation 451 m (1,480 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 118.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Altoona 7 SW (16 km)
- Raystown Lake 2 (23 km)
- Raystown HQ (23 km)
- Altoona 3 W (25 km)
- Everett (32 km)
- Wolfsburg (33 km)
- Ebensburg Sewage Plant (40 km)
- Shawnee State Park (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.