Dover, DE 19901 Frost Dates
19901, near Dover, DE: the frost window
The last spring frost here typically falls around 04/04, about 219 days from today. Fall's first freeze usually shows up around 11/04, roughly 214 days after the last spring frost.
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 Dover, not a forecast for this year.
Stretching the season past the first frost
Dover's growing season runs out in roughly 10 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/17 and only about 1 year in 10 sees frost after that.
Dover against the rest of the dataset
About 214 days separate Dover's last and first frost, putting it 14,218 of 40,283 ZIP codes nationally. Within DE, it ranks 13 of 96.
Learn more
Two guides worth reading on 19901: zone vs. frost date, on why Zone 7b and Dover's frost date answer different questions, and the frost range, on how to read the range around Dover's dates instead of trusting one.