Frost Dates for 23518 — Norfolk, Virginia

Half of springs at Norfolk International Airport, VA see their last 32°F night by March 17; only one in ten is past it by February 27, and one in ten still has one after March 31. Planting tender crops after March 23 leaves a 30% risk of a frost on them, after March 27 20%, and after March 31 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 80% of the 128 Virginia stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 23 in half of years, as early as November 8 one year in ten, and holds off past December 10 one year in ten. A hard freeze of 28°F follows 15 days later, around December 8; in spring the one-in-ten date for 28°F is March 20, 11 days before the 32°F one. The freeze-free season lasts 252 days in a typical year, longer than at 99% of the 128 Virginia stations; it reaches 275 days one year in ten and falls short of 231 one year in ten. On average 41 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 30, and return around November 11. Nights of 24°F, cold enough to damage hardier plants, come in 97% of winters and 16°F in 41%.

July is the warmest month at Norfolk International Airport, VA, averaging 89°F by day and 73°F at night; January is the coldest at 51°F and 34°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 87% of years.

Warmth for growing adds up to 5,132 growing degree days a year (base 50°F), more than at 99% of the 128 Virginia stations. 37% of them (1,894) have built up by the end of June, and July adds the most, 964. Precipitation totals 49.3 inches a year, most in July (6.1") and least in February (2.9"); May to September bring 52% of it.

The nearest other station, Norfolk S, VA, 3 miles south of Norfolk, has a last frost 6 days later (March 23), a first frost 7 days earlier (November 16), a season 13 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, 1.7 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 24 days after the last snow.

ZIP 23518 is 2 miles from Norfolk International Airport, VA, which stands at 30 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 23455 (Virginia Beach). The 2023 USDA Plant Hardiness Zone Map lists ZIP 23518 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.