Accident, MD 21520 Frost Dates
Frost dates for Accident, MD, ZIP 21520
Around 05/09 is the usual last spring frost, about 254 days away. The first fall frost typically arrives around 10/11, about 155 frost-free days later.
The USDA Plant Hardiness Zone Map puts Accident in Zone 6a (-10 to -5°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
Zone 6a around Accident has about 6 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/09 is the middle of 30 years of NOAA records, not a promise. Plant by 04/21 and you're betting against frost in roughly 9 years out of 10. 05/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Accident compares
Accident's growing season runs about 155 days, ranking 34,117 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 582 of 583.
Learn more
local microclimates explains what one yard in Accident can differ from the 21520 normal, and zone vs. frost date explains why Zone 6a and Accident's frost date answer different questions.