Millbourne, PA 19139 Frost Dates
19139, near Millbourne, PA: the frost window
Typically, the last spring freeze lands around 04/02, roughly 217 days out. Fall's first freeze usually shows up around 11/10, roughly 224 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Millbourne in Zone 7b (5 to 10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Millbourne's growing season runs out in roughly 11 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Millbourne's last frost
04/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/13 and only about 1 year in 10 sees frost after that.
Millbourne against the rest of the dataset
About 224 days separate Millbourne's last and first frost, putting it 11,925 of 40,283 ZIP codes nationally. Within PA, it ranks 43 of 2,088.
Learn more
Two guides worth reading on 19139: local microclimates, on what one yard in Millbourne can differ from the 19139 normal, and zone vs. frost date, on why Zone 7b and Millbourne's frost date answer different questions.