Gaithersburg, MD 20813 Frost Dates
When can you plant in Gaithersburg, MD?
Typically, the last spring freeze lands around 04/01, roughly 216 days out. The first fall frost typically arrives around 11/06, about 219 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 Gaithersburg, not a forecast for this year.
What to do before the first frost
About 10 weeks of growing season left in Gaithersburg before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Gaithersburg's last frost
04/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/19 and you're betting against frost in roughly 9 years out of 10. 04/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Gaithersburg compares
Gaithersburg's growing season runs about 219 days, ranking 12,924 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 197 of 583.
Learn more
local microclimates covers what one yard in Gaithersburg can differ from the 20813 normal. zone vs. frost date covers why Zone 7b and Gaithersburg's frost date answer different questions.