Portsmouth, VA 23704 Frost Dates
Frost dates for Portsmouth, VA, ZIP 23704
The last spring frost here typically falls around 03/23, about 207 days from today. The first fall frost typically arrives around 11/16, about 239 frost-free days later.
Zone 8b (15 to 20°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 Portsmouth, not a forecast for this year.
What to do before the first frost
Zone 8b around Portsmouth has about 11 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 03/23 isn't a guarantee
03/23 is the middle of 30 years of NOAA records, not a promise. Plant by 03/07 and you're betting against frost in roughly 9 years out of 10. 04/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Portsmouth compares
Portsmouth's growing season runs about 239 days, ranking 8,764 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 68 of 1,178.
Learn more
the frost range explains how to read the range around Portsmouth's dates instead of trusting one, and local microclimates explains what one yard in Portsmouth can differ from the 23704 normal.