Manassas, VA 20109 Frost Dates
Frost dates for Manassas, VA, ZIP 20109
Typically, the last spring freeze lands around 04/15, roughly 230 days out. The first fall frost typically arrives around 10/24, about 194 frost-free days later.
Manassas sits in USDA Zone 7a (0 to 5°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.
What to do before the first frost
Zone 7a around Manassas has about 8 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.
Why 04/15 isn't a guarantee
04/15 is the middle of 30 years of NOAA records, not a promise. Plant by 03/31 and you're betting against frost in roughly 9 years out of 10. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Manassas compares
Manassas's growing season runs about 194 days, ranking 19,419 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 747 of 1,178.
Learn more
local microclimates explains what one yard in Manassas can differ from the 20109 normal, and zone vs. frost date explains why Zone 7a and Manassas's frost date answer different questions.