Frost dates for Williamsport 2, PA
At Williamsport 2, the median last spring frost (32°F) is Apr 25 and the median first fall frost is Oct 24, 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 zones 6a to 6b.
- Apr 25Last spring frost (median)50% chance of 32°F after this date
- May 12Safer planting date10% chance of 32°F after this date
- Oct 24First 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 21 | May 7 | May 23 |
| 32°F | Apr 10 | Apr 25 | May 12 |
| 28°F | Mar 29 | Apr 10 | Apr 25 |
| 24°F | Mar 15 | Mar 30 | Apr 10 |
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 29 | Oct 11 | Oct 25 |
| 32°F | Oct 8 | Oct 24 | Nov 5 |
| 28°F | Oct 20 | Nov 4 | Nov 18 |
| 24°F | Nov 2 | Nov 15 | 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 | 158 days | 177 days |
| 32°F | 161 days | 181 days | 202 days |
| 28°F | 185 days | 206 days | 226 days |
| 24°F | 212 days | 230 days | 250 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 |
|---|---|---|---|
| 17702 | 6b | -5 to 0°F | 11 km |
| 17728 | 6a | -10 to -5°F | 12 km |
| 17744 | 6b | -5 to 0°F | 14 km |
| 17810 | 6b | -5 to 0°F | 17 km |
| 17720 | 6b | -5 to 0°F | 20 km |
| 17771 | 6a | -10 to -5°F | 21 km |
| 17776 | 6a | -10 to -5°F | 32 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 USC00369735, at 41.2486, -76.9833, elevation 160 m (525 ft).
- Data quality: Representative (10+ years), 22 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
- Williamsport (5 km)
- Lewisburg (35 km)
- Lock Haven Sewage Plant (40 km)
- Laurelton Center (43 km)
- Laporte (45 km)
- Canton (46 km)
- Sunbury (47 km)
- Selinsgrove Penn Valley Airport (49 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.