Unionville, PA 16844 Frost Dates
Unionville, PA: when does the frost end?
Typically, the last spring freeze lands around 04/20, roughly 235 days out. Fall's first freeze usually shows up around 10/26, roughly 187 days after the last spring frost.
Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Unionville, not a forecast for this year.
Stretching the season past the first frost
With roughly 8 weeks until Unionville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Unionville's last frost
04/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Unionville against the rest of the dataset
Unionville's growing season runs about 187 days, ranking 22,603 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 626 of 2,088.
Learn more
Before leaning on 16844's figures: the frost range explains how to read the range around Unionville's dates instead of trusting one, while local microclimates explains what one yard in Unionville can differ from the 16844 normal.