Greenbelt, MD 20770 Frost Dates
20770, near Greenbelt, MD: the frost window
The last spring frost here typically falls around 04/10, about 225 days from today. Fall's first freeze usually shows up around 11/01, roughly 202 days after the last spring frost.
Greenbelt sits in USDA Zone 7b (5 to 10°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
Greenbelt's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Greenbelt's last frost
04/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Greenbelt against the rest of the dataset
At roughly 202 frost-free days, Greenbelt places 17,144 of 40,283 ZIP codes in this dataset. Within MD, it ranks 417 of 583.
Learn more
Two guides worth reading on 20770: zone vs. frost date, on why Zone 7b and Greenbelt's frost date answer different questions, and the frost range, on how to read the range around Greenbelt's dates instead of trusting one.