Frost Dates for 23511 — Norfolk, Virginia

Half of springs at Norfolk NAS, VA see their last 32°F night by March 16; only one in ten is past it by February 26, and one in ten still has one after April 1. Planting tender crops after March 23 leaves a 30% risk of a frost on them, after March 27 20%, and after April 1 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 59% of the 128 Virginia stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 26 in half of years, as early as November 8 one year in ten, and holds off past December 17 one year in ten. A hard freeze of 28°F follows 16 days later, around December 12; in spring the one-in-ten date for 28°F is March 19, 13 days before the 32°F one. The freeze-free season lasts 255 days in a typical year, the longest of the 128 Virginia stations; it reaches 283 days one year in ten and falls short of 231 one year in ten. On average 33 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 13 days longer, to about March 29, and return around November 14. Nights of 24°F, cold enough to damage hardier plants, come in 98% of winters and 16°F in 42%.

July is the warmest month at Norfolk NAS, VA, averaging 89°F by day and 73°F at night; January is the coldest at 50°F and 34°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 85% of years and April still brings one in 10% of years.

Warmth for growing adds up to 5,062 growing degree days a year (base 50°F), more than at 98% of the 128 Virginia stations. 37% of them (1,867) have built up by the end of June, and July adds the most, 950. Precipitation totals 45.7 inches a year, most in August (5.3") and least in February (2.6"); May to September bring 52% of it.

The nearest other station, Norfolk S, VA, 6 miles southeast of Norfolk, has a last frost 7 days later (March 23), a first frost 10 days earlier (November 16), a season 16 days shorter.

The first measurable snow (0.1 inch or more) in Norfolk usually arrives around January 14, and the last of the season around February 21. Those are the middle dates across the winters of 1991–2020 at Norfolk International Airport, VA, 6.5 miles away: half of years saw snow earlier, half later. Snow fell in 83% of those winters. The last 32°F night of spring typically comes 23 days after the last snow.

ZIP 23511 is 2 miles from Norfolk NAS, VA, which stands at 17 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 23503 (Norfolk). The 2023 USDA Plant Hardiness Zone Map lists ZIP 23511 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.