Allentown, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Allentown, a city in Lehigh County, Pennsylvania.
Overnight
54°F
Mostly Clear
Mostly clear, with a low around 54. North wind around 5 mph.
7-day forecast for Allentown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 54°F | Mostly Clear | 5 mph N | 0% |
| Saturday | 73°F | Mostly Sunny | 5 mph E | 1% |
| Saturday Night | 59°F | Patchy Fog | 5 mph SE | 52% |
| Sunday | 71°F | Rain Showers | 5 to 10 mph S | 92% |
| Sunday Night | 59°F | Patchy Fog | 0 to 5 mph W | 92% |
| Monday | 67°F | Chance Rain Showers | 5 to 10 mph NE | 34% |
| Monday Night | 53°F | Chance Rain Showers | 5 to 10 mph NE | 31% |
| Tuesday | 63°F | Chance Rain Showers | 10 mph NE | 37% |
| Tuesday Night | 51°F | Chance Rain Showers | 10 mph NE | 35% |
| Wednesday | 62°F | Chance Rain Showers | 10 to 15 mph NE | 33% |
| Wednesday Night | 50°F | Chance Showers And Thunderstorms | 10 mph NE | 39% |
| Thursday | 62°F | Chance Showers And Thunderstorms | 10 mph NE | 35% |
| Thursday Night | 51°F | Chance Showers And Thunderstorms | 5 to 10 mph NE | 32% |
| Friday | 69°F | Slight Chance Rain Showers | 5 to 10 mph N | 20% |
Forecast source: National Weather Service (api.weather.gov) for Allentown (40.594, -75.478). Updated through the day.
Growing snapshot for Allentown
Last spring frost
Apr 20
First fall frost
Oct 24
Growing season
184 days
More local growing data for Allentown: nearby ZIP 18101 weather · frost dates · planting calendar · Pennsylvania frost dates
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Climate data from the nearest NOAA station, Allentown Intl Ap, Pa (3.5 mi from Allentown). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.