Frost dates for Lancaster Airport, PA
At Lancaster Airport, the median last spring frost (32°F) is Apr 18 and the median first fall frost is Oct 25, for a typical growing season of 186 days. For a 90% chance that the last frost has passed, wait until May 5. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 18Last spring frost (median)50% chance of 32°F after this date
- May 5Safer planting date10% chance of 32°F after this date
- Oct 25First fall frost (median)50% chance of 32°F by this date
- 186 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 18 | May 1 | May 16 |
| 32°F | Apr 4 | Apr 18 | May 5 |
| 28°F | Mar 21 | Apr 4 | Apr 18 |
| 24°F | Mar 9 | 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 2 | Oct 14 | Oct 27 |
| 32°F | Oct 10 | Oct 25 | Nov 6 |
| 28°F | Oct 23 | Nov 5 | Nov 20 |
| 24°F | Nov 2 | Nov 18 | Dec 5 |
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 | 146 days | 165 days | 183 days |
| 32°F | 166 days | 186 days | 207 days |
| 28°F | 192 days | 214 days | 236 days |
| 24°F | 217 days | 239 days | 263 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 |
|---|---|---|---|
| 17606 | 7a | 0 to 5°F | 1 km |
| 17520 | 7a | 0 to 5°F | 5 km |
| 17543 | 7a | 0 to 5°F | 7 km |
| 17508 | 7a | 0 to 5°F | 7 km |
| 17501 | 7a | 0 to 5°F | 9 km |
| 17522 | 7a | 0 to 5°F | 12 km |
| 17578 | 7a | 0 to 5°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 USW00054737, at 40.1203, -76.2944, elevation 123 m (403 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 109.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lancaster 2ne Fltr Plant (8 km)
- Landisville 2 NW (11 km)
- New Holland 2 SE (20 km)
- Safe Harbor Dam (23 km)
- Lebanon 2 W (28 km)
- Hopewell Morgantown (35 km)
- Blue Marsh Lake (37 km)
- Reading Spaatz Field (39 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.