Fairfax, VA 22158 Frost Dates
Frost dates for Fairfax, VA, ZIP 22158
The last spring frost here typically falls around 04/14, about 229 days from today. The first fall frost typically arrives around 10/29, about 198 frost-free days later.
Zone 7b (5 to 10°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 Fairfax, not a forecast for this year.
What to do before the first frost
Zone 7b around Fairfax has about 9 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 04/14 isn't a guarantee
04/14 is the middle of 30 years of NOAA records, not a promise. Plant by 03/30 and you're betting against frost in roughly 9 years out of 10. 04/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Fairfax compares
Fairfax's growing season runs about 198 days, ranking 18,340 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 680 of 1,178.
Learn more
local microclimates explains what one yard in Fairfax can differ from the 22158 normal, and zone vs. frost date explains why Zone 7b and Fairfax's frost date answer different questions.