FrostDateCheck

Portsmouth, VA 23510 Frost Dates

23510, near Portsmouth, VA: the frost window

Zone 8b

The last spring frost here typically falls around 03/23, about 207 days from today. Fall's first freeze usually shows up around 11/16, roughly 239 days after the last spring frost.

Portsmouth sits in USDA Zone 8b (15 to 20°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.

Stretching the season past the first frost

Portsmouth's growing season runs out in roughly 11 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.

How much risk comes with planting early here

03/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/06 and only about 1 year in 10 sees frost after that.

Portsmouth against the rest of the dataset

Portsmouth's growing season runs about 239 days, ranking 8,759 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 63 of 1,178.

Learn more

Two guides worth reading on 23510: the frost range, on how to read the range around Portsmouth's dates instead of trusting one, and local microclimates, on what one yard in Portsmouth can differ from the 23510 normal.