Frost Dates for 37404 — Chattanooga, Tennessee

Half of springs at Chattanooga Lovell Airport, TN see their last 32°F night by March 24; only one in ten is past it by March 6, 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 78% of the 144 Tennessee stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 9 in half of years, as early as October 27 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 13 days later, around November 22; in spring the one-in-ten date for 28°F is March 30, 9 days before the 32°F one. The freeze-free season lasts 230 days in a typical year, longer than at 98% of the 144 Tennessee stations; it reaches 254 days one year in ten and falls short of 210 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 31. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 73%.

July is the warmest month at Chattanooga Lovell Airport, TN, averaging 91°F by day and 71°F at night; January is the coldest at 51°F and 32°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 28% of years.

Warmth for growing adds up to 5,216 growing degree days a year (base 50°F), more than at 97% of the 144 Tennessee stations. 39% of them (2,050) have built up by the end of June, and July adds the most, 953. Precipitation totals 55.0 inches a year, most in March (5.3") and least in October (3.6"); May to September bring 38% of it.

The nearest other station, Lookout Mountain-Point Park, TN, 4 miles west of Chattanooga and 1,439 feet higher, has a last frost 7 days later (March 31), a first frost 3 days earlier (November 6), a season 11 days shorter.

Measurable snow is rare here: only 0 of 17 winters from 1991 to 2020 recorded 0.1 inch or more at Chickamauga Park, GA, 9 miles away, so there is no typical first-snow date to plan around.

ZIP 37404 is 4 miles from Chattanooga Lovell Airport, TN, which stands at 671 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 8 other ZIP codes share the station; its figures are presented in full for 37421 (Chattanooga). The 2023 USDA Plant Hardiness Zone Map lists ZIP 37404 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.