FrostDateCheck

Wilmington, DE 19801 Frost Dates

Frost dates for Wilmington, DE, ZIP 19801

Zone 7b

The last spring frost here typically falls around 04/07, about 222 days from today. The first fall frost typically arrives around 11/04, about 209 frost-free days later.

Zone 7b (5 to 10°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 Wilmington, not a forecast for this year.

What to do before the first frost

Zone 7b around Wilmington has about 10 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.

The actual range around Wilmington's last frost

04/07 is the middle of 30 years of NOAA records, not a promise. Plant by 03/26 and you're betting against frost in roughly 9 years out of 10. 04/24 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Wilmington compares

At roughly 209 frost-free days, Wilmington places 15,137 of 40,283 ZIP codes in this dataset. Within DE, it ranks 31 of 96.

Learn more

zone vs. frost date explains why Zone 7b and Wilmington's frost date answer different questions, and the frost range explains how to read the range around Wilmington's dates instead of trusting one.