FrostDateCheck

Allentown, PA 18102 Frost Dates

Allentown, PA: when does the frost end?

Zone 7a

The last spring frost here typically falls around 04/20, about 235 days from today. Fall's first freeze usually shows up around 10/24, roughly 184 days after the last spring frost.

Allentown sits in USDA Zone 7a (0 to 5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.

Stretching the season past the first frost

With roughly 8 weeks until Allentown's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.

The actual range around Allentown's last frost

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.

Allentown against the rest of the dataset

At roughly 184 frost-free days, Allentown places 23,386 of 40,283 ZIP codes in this dataset. Within PA, it ranks 752 of 2,088.

Learn more

Before leaning on 18102's figures: the frost range explains how to read the range around Allentown's dates instead of trusting one, while local microclimates explains what one yard in Allentown can differ from the 18102 normal.