Mount Airy, MD 21765 Frost Dates
21765, near Mount Airy, MD: the frost window
Around 04/14 is the usual last spring frost, about 229 days away. Fall's first freeze usually shows up around 10/29, roughly 196 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Mount Airy in Zone 7b (5 to 10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Mount Airy'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.
How much risk comes with planting early here
04/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/31 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/02 and only about 1 year in 10 sees frost after that.
Mount Airy against the rest of the dataset
At roughly 196 frost-free days, Mount Airy places 18,940 of 40,283 ZIP codes in this dataset. Within MD, it ranks 483 of 583.
Learn more
Two guides worth reading on 21765: zone vs. frost date, on why Zone 7b and Mount Airy's frost date answer different questions, and the frost range, on how to read the range around Mount Airy's dates instead of trusting one.