Frost Dates for 35806 — Huntsville, Alabama

Half of springs at Huntsville International Airport, AL see their last 32°F night by March 24; only one in ten is past it by March 4, and one in ten still has one after April 8. Planting tender crops after March 31 leaves a 30% risk of a frost on them, after April 3 20%, and after April 8 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 92% of the 115 Alabama stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 8 in half of years, as early as October 27 one year in ten, and holds off past November 25 one year in ten. A hard freeze of 28°F follows 12 days later, around November 20; in spring the one-in-ten date for 28°F is March 29, 10 days before the 32°F one. The freeze-free season lasts 229 days in a typical year, shorter than at 56% of the 115 Alabama stations; it reaches 255 days one year in ten and falls short of 208 one year in ten. On average 56 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 11 days longer, to about April 4, and return around October 30. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 77%.

July is the warmest month at Huntsville International Airport, AL, averaging 92°F by day and 71°F at night; January is the coldest at 52°F and 33°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 27% of years.

Warmth for growing adds up to 5,547 growing degree days a year (base 50°F), more than at 50% of the 115 Alabama stations. 40% of them (2,226) have built up by the end of June, and July adds the most, 970. Precipitation totals 54.6 inches a year, most in December (5.9") and least in September (3.5"); May to September bring 37% of it.

The nearest other station, Belle Mina 2 N, AL, 12 miles west of Huntsville, has a last frost 7 days later (March 31), a first frost 7 days earlier (November 1), a season 15 days shorter.

Measurable snow is rare here: only 10 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Athens, AL, 15.3 miles away, so there is no typical first-snow date to plan around.

ZIP 35806 is 9 miles from Huntsville International Airport, AL, which stands at 624 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 35758 (Madison). The 2023 USDA Plant Hardiness Zone Map lists ZIP 35806 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.