Harman US

Unionville, PA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Unionville, a community in Chester County, Pennsylvania.

This Afternoon
72°F
Mostly Sunny
Mostly sunny, with a high near 72. South wind 5 to 10 mph.

7-day forecast for Unionville

WhenTempForecastWindPrecip
This Afternoon 72°F Mostly Sunny 5 to 10 mph S 2%
Tonight 57°F Mostly Cloudy 5 mph S 3%
Thursday 70°F Light Rain Likely 5 to 10 mph S 60%
Thursday Night 59°F Light Rain 0 to 5 mph SW 82%
Friday 68°F Light Rain 0 to 5 mph N 82%
Friday Night 48°F Light Rain Likely 0 to 5 mph NW 63%
Saturday 62°F Mostly Sunny 5 to 10 mph NW 7%
Saturday Night 40°F Partly Cloudy 5 to 10 mph W 7%
Sunday 58°F Mostly Sunny 5 to 10 mph NW 5%
Sunday Night 38°F Mostly Clear 5 mph W 6%
Monday 57°F Sunny 10 mph W 6%
Monday Night 36°F Mostly Clear 5 mph W 4%
Tuesday 61°F Sunny 5 to 10 mph W 3%
Tuesday Night 38°F Mostly Clear 5 mph W 0%

Forecast source: National Weather Service (api.weather.gov) for Unionville (39.901, -75.730). Updated through the day.

Growing snapshot for Unionville

Last spring frost
Apr 19
First fall frost
Oct 26
Growing season
189 days
Hardiness zone
7a

More local growing data for Unionville: nearby ZIP 19375 weather · frost dates · planting calendar · Pennsylvania frost dates

Nearby towns & communities

All Pennsylvania locations ›

Climate data from the nearest NOAA station, Avondale 2 N, Pa (3.8 mi from Unionville). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.