Allentown, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Allentown, a city in Lehigh County, Pennsylvania.
Today
74°F
Sunny
Sunny, with a high near 74. South wind 0 to 5 mph.
7-day forecast for Allentown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 74°F | Sunny | 0 to 5 mph S | 2% |
| Tonight | 58°F | Mostly Cloudy | 0 to 5 mph S | 9% |
| Thursday | 72°F | Light Rain Likely | 5 to 10 mph S | 72% |
| Thursday Night | 59°F | Light Rain | 0 to 5 mph SW | 81% |
| Friday | 70°F | Light Rain Likely | 0 mph | 55% |
| Friday Night | 48°F | Chance Light Rain then Partly Cloudy | 0 mph | 40% |
| Saturday | 64°F | Mostly Sunny then Slight Chance Light Rain | 0 to 10 mph W | 18% |
| Saturday Night | 41°F | Slight Chance Light Rain | 5 mph W | 18% |
| Sunday | 60°F | Mostly Sunny | 5 to 10 mph NW | 5% |
| Sunday Night | 37°F | Partly Cloudy | 5 mph W | 4% |
| Monday | 58°F | Sunny | 5 to 10 mph W | 6% |
| Monday Night | 35°F | Mostly Clear | 5 mph W | 4% |
| Tuesday | 63°F | Sunny | 5 to 10 mph W | 3% |
| Tuesday Night | 37°F | Mostly Clear | 5 mph W | 0% |
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 Nov 4, 2026.