Upper Marlboro, MD 20772 Frost Dates
When can you plant in Upper Marlboro, MD?
Around 04/09 is the usual last spring frost, about 224 days away. The first fall frost typically arrives around 10/29, about 203 frost-free days later.
The USDA Plant Hardiness Zone Map puts Upper Marlboro in Zone 7b (5 to 10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 9 weeks of growing season left in Upper Marlboro before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/09 isn't a guarantee
04/09 is the middle of 30 years of NOAA records, not a promise. Plant by 03/27 and you're betting against frost in roughly 9 years out of 10. 04/24 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Upper Marlboro compares
About 203 days separate Upper Marlboro's last and first frost, putting it 17,006 of 40,283 ZIP codes nationally. Within MD, it ranks 412 of 583.
Learn more
the frost range covers how to read the range around Upper Marlboro's dates instead of trusting one. local microclimates covers what one yard in Upper Marlboro can differ from the 20772 normal.