Last frost date in Allentown, Pennsylvania
April 20
Average last frost in spring. In an early year (1 in 10) it's over by April 6; in a late year (1 in 10) it comes after May 6.
October 24
Average first frost in fall. 1 year in 10 it comes by October 8.
Source: NOAA U.S. Climate Normals 1991–2020, station Allentown International AP (USW00014737), 4.2 miles from Allentown, elevation 390 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
This station is also the nearest one for Bethlehem, Emmaus and Northampton, so their frost dates are the same as Allentown's.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Apr 6 | Apr 20 | May 6 |
| First frost in fall | Oct 8 | Oct 24 | Nov 6 |
Frost-free days in an average year: 184
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | May 2 | Oct 12 |
| Frost (32°F) | Every year | Apr 20 | Oct 24 |
| Hard freeze (28°F) | Every year | Apr 5 | Nov 4 |
Nights at 32°F or colder in an average year: 118
What to plant now in Allentown
- Spring planting calendar for an average last frost around April 20 Allentown: April 20
- Fall planting calendar for an average first frost around October 20 Allentown: October 24
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in Pennsylvania
- Easton 15 mi · last frost Apr 18
- Pottstown 25 mi · last frost Apr 20
- Lansdale 26 mi · last frost Apr 11
- Reading 29 mi · last frost Apr 14
- Phoenixville 32 mi · last frost Apr 18
Updated