Allentown, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Allentown, a city in Lehigh County, Pennsylvania.
Overnight
48°F
Mostly Clear
Mostly clear, with a low around 48. Wind around 0 mph.
7-day forecast for Allentown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 48°F | Mostly Clear | 0 mph | 1% |
| Wednesday | 74°F | Sunny | 0 to 5 mph S | 2% |
| Wednesday Night | 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% |
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
Nearby towns & communities
Alburtis
Ancient Oaks
Bethlehem
Breinigsville
Catasauqua
Cementon
Cetronia
Coopersburg
Coplay
DeSales University
Dorneyville
Egypt
Emmaus
Fountain Hill
Fullerton
Hokendauqua
Laurys Station
Macungie
New Tripoli
North Catasauqua
Schnecksville
Slatedale
Slatington
Stiles
Trexlertown
Wescosville
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.