Gaithersburg, MD 20878 Frost Dates
Gaithersburg, MD: when does the frost end?
Around 04/01 is the usual last spring frost, about 216 days away. Fall's first freeze usually shows up around 11/06, roughly 219 days after the last spring frost.
Gaithersburg 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
With roughly 10 weeks until Gaithersburg's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Gaithersburg's last frost
04/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/15 and only about 1 year in 10 sees frost after that.
Gaithersburg against the rest of the dataset
Gaithersburg's growing season runs about 219 days, ranking 12,934 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 207 of 583.
Learn more
Before leaning on 20878's figures: the frost range explains how to read the range around Gaithersburg's dates instead of trusting one, while local microclimates explains what one yard in Gaithersburg can differ from the 20878 normal.