Bethlehem, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Bethlehem, a city in Lehigh County, Pennsylvania.
Today
85°F
Mostly Sunny
Mostly sunny, with a high near 85. Northeast wind around 0 mph.
7-day forecast for Bethlehem
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 85°F | Mostly Sunny | 0 mph | 0% |
| Tonight | 64°F | Mostly Cloudy | 0 mph | 2% |
| Wednesday | 84°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 0 mph | 54% |
| Wednesday Night | 70°F | Showers And Thunderstorms Likely | 0 mph | 60% |
| Thursday | 89°F | Showers And Thunderstorms Likely | 0 to 5 mph SW | 72% |
| Thursday Night | 72°F | Showers And Thunderstorms Likely | 0 to 5 mph SW | 72% |
| Friday | 89°F | Mostly Sunny then Showers And Thunderstorms Likely | 0 to 5 mph SW | 56% |
| Friday Night | 70°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 0 to 5 mph W | 56% |
| Saturday | 87°F | Partly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph W | 43% |
| Saturday Night | 69°F | Chance Showers And Thunderstorms | 0 to 5 mph W | 43% |
| Sunday | 88°F | Mostly Sunny | 0 to 5 mph W | 12% |
| Sunday Night | 70°F | Mostly Clear | 0 to 5 mph SW | 12% |
| Monday | 90°F | Sunny then Slight Chance Showers And Thunderstorms | 0 to 10 mph W | 16% |
| Monday Night | 69°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph W | 16% |
Forecast source: National Weather Service (api.weather.gov) for Bethlehem (40.626, -75.368). Updated through the day.
Growing snapshot for Bethlehem
Last spring frost
Apr 20
First fall frost
Oct 24
Growing season
184 days
Hardiness zone
7a
More local growing data for Bethlehem: nearby ZIP 18018 weather · frost dates · planting calendar · Pennsylvania frost dates
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Climate data from the nearest NOAA station, Allentown Intl Ap, Pa (3.2 mi from Bethlehem). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.