FrostDateCheck

Emmaus, PA 18049 Frost Dates

18049, near Emmaus, PA: the frost window

Zone 7a

Around 04/20 is the usual last spring frost, about 235 days away. Fall's first freeze usually shows up around 10/24, roughly 184 days after the last spring frost.

The USDA Plant Hardiness Zone Map puts Emmaus in Zone 7a (0 to 5°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

Emmaus's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.

Why 04/20 isn't a guarantee

04/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/06 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.

Emmaus against the rest of the dataset

About 184 days separate Emmaus's last and first frost, putting it 23,462 of 40,283 ZIP codes nationally. Within PA, it ranks 757 of 2,088.

Learn more

Two guides worth reading on 18049: local microclimates, on what one yard in Emmaus can differ from the 18049 normal, and zone vs. frost date, on why Zone 7a and Emmaus's frost date answer different questions.