Frost dates for Reading Spaatz Field, PA
At Reading Spaatz Field, the median last spring frost (32°F) is Apr 14 and the median first fall frost is Oct 29, for a typical growing season of 197 days. For a 90% chance that the last frost has passed, wait until Apr 30. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 14Last spring frost (median)50% chance of 32°F after this date
- Apr 30Safer planting date10% chance of 32°F after this date
- Oct 29First 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 14 | Apr 28 | May 13 |
| 32°F | Apr 1 | Apr 14 | Apr 30 |
| 28°F | Mar 17 | Apr 1 | Apr 15 |
| 24°F | Mar 5 | Mar 21 | Apr 3 |
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 4 | Oct 17 | Nov 1 |
| 32°F | Oct 13 | Oct 29 | Nov 10 |
| 28°F | Oct 25 | Nov 8 | Nov 24 |
| 24°F | Nov 5 | Nov 21 | Dec 8 |
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 | 152 days | 172 days | 193 days |
| 32°F | 173 days | 197 days | 217 days |
| 28°F | 201 days | 221 days | 243 days |
| 24°F | 223 days | 244 days | 268 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 |
|---|---|---|---|
| 19601 | 7a | 0 to 5°F | 3 km |
| 19610 | 7a | 0 to 5°F | 3 km |
| 19604 | 7a | 0 to 5°F | 5 km |
| 19609 | 7a | 0 to 5°F | 5 km |
| 19611 | 7a | 0 to 5°F | 5 km |
| 19602 | 7a | 0 to 5°F | 6 km |
| 19607 | 7a | 0 to 5°F | 9 km |
| 19606 | 7a | 0 to 5°F | 10 km |
| 19535 | 7a | 0 to 5°F | 15 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 USW00014712, at 40.3667, -75.9667, elevation 104 m (341 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 107.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Blue Marsh Lake (5 km)
- Reading 4 NNW (7 km)
- Hamburg (21 km)
- Hopewell Morgantown (24 km)
- Rodale Rsch Center (29 km)
- New Holland 2 SE (34 km)
- Glenmoore (35 km)
- Pottstown Limerick Airport (38 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.