Frost Dates for 35242 — Birmingham, Alabama

Half of springs at Birmingham Airport, AL see their last 32°F night by March 21; only one in ten is past it by February 28, and one in ten still has one after April 8. Planting tender crops after March 30 leaves a 30% risk of a frost on them, after April 2 20%, and after April 8 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 46% of the 115 Alabama stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 11 in half of years, as early as October 30 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 13 days later, around November 24; in spring the one-in-ten date for 28°F is March 26, 13 days before the 32°F one. The freeze-free season lasts 236 days in a typical year, longer than at 58% of the 115 Alabama stations; it reaches 262 days one year in ten and falls short of 211 one year in ten. On average 47 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 April 3, and return around November 2. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 65%.

July is the warmest month at Birmingham Airport, AL, averaging 91°F by day and 72°F at night; January is the coldest at 55°F and 35°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September 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 26% of years.

Warmth for growing adds up to 5,764 growing degree days a year (base 50°F), more than at 61% of the 115 Alabama stations. 40% of them (2,323) have built up by the end of June, and July adds the most, 978. Precipitation totals 56.7 inches a year, most in March (5.7") and least in October (3.3"); May to September bring 41% of it.

The nearest other station, Helena, AL, 12 miles southwest of Birmingham, has a last frost 2 days earlier (March 19), a first frost 3 days earlier (November 8).

Measurable snow is rare here: only 1 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Leeds, AL, 10.3 miles away, so there is no typical first-snow date to plan around.

ZIP 35242 is 11 miles from Birmingham Airport, AL, which stands at 615 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 26 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 35242 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.