Williamsport, MD 21733 Frost Dates
When can you plant in Williamsport, MD?
Typically, the last spring freeze lands around 04/11, roughly 226 days out. The first fall frost typically arrives around 10/28, about 199 frost-free days later.
Zone 7a (0 to 5°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 Williamsport, not a forecast for this year.
What to do before the first frost
About 9 weeks of growing season left in Williamsport before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/11 is the middle of 30 years of NOAA records, not a promise. Plant by 03/29 and you're betting against frost in roughly 9 years out of 10. 04/27 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williamsport compares
About 199 days separate Williamsport's last and first frost, putting it 18,135 of 40,283 ZIP codes nationally. Within MD, it ranks 472 of 583.
Learn more
local microclimates covers what one yard in Williamsport can differ from the 21733 normal. zone vs. frost date covers why Zone 7a and Williamsport's frost date answer different questions.