FrostDateCheck

Macungie, PA 18092 Frost Dates

When can you plant in Macungie, PA?

Zone 7a

Typically, the last spring freeze lands around 04/26, roughly 241 days out. The first fall frost typically arrives around 10/17, about 175 frost-free days later.

Macungie 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.

What to do before the first frost

About 7 weeks of growing season left in Macungie before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around Macungie's last frost

04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/12 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Macungie compares

Macungie's growing season runs about 175 days, ranking 26,926 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,154 of 2,088.

Learn more

local microclimates covers what one yard in Macungie can differ from the 18092 normal. zone vs. frost date covers why Zone 7a and Macungie's frost date answer different questions.