Frost Dates for 37375 — Sewanee, Tennessee

Half of springs at Sewanee, TN see their last 32°F night by April 2; only one in ten is past it by March 16, and one in ten still has one after April 18. Planting tender crops after April 8 leaves a 30% risk of a frost on them, after April 11 20%, and after April 18 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 53% of the 144 Tennessee stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 4 in half of years, as early as October 22 one year in ten, and holds off past November 22 one year in ten. A hard freeze of 28°F follows 12 days later, around November 16; in spring the one-in-ten date for 28°F is April 7, 11 days before the 32°F one. The freeze-free season lasts 216 days in a typical year, longer than at 83% of the 144 Tennessee stations; it reaches 240 days one year in ten and falls short of 196 one year in ten. On average 68 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 13, and return around October 25. Severe cold of 16°F or below comes in 99% of winters, usually between December 29 and February 15.

July is the warmest month at Sewanee, TN, averaging 84°F by day and 66°F at night; January is the coldest at 45°F and 29°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 53% of years.

Warmth for growing adds up to 4,084 growing degree days a year (base 50°F), fewer than at 78% of the 144 Tennessee stations. 38% of them (1,546) have built up by the end of June, and July adds the most, 780. Precipitation totals 64.1 inches a year, most in April (6.4") and least in October (4.2"); May to September bring 41% of it.

The nearest other station, Monteagle, TN, 4 miles northeast of Sewanee, has a last frost 8 days later (April 10), a first frost 7 days earlier (October 28), a season 15 days shorter.

The first measurable snow (0.1 inch or more) in Sewanee usually arrives around January 10, and the last of the season around February 22. Those are the middle dates across the winters of 1991–2020 at Monteagle, TN, 4.4 miles away: half of years saw snow earlier, half later. Snow fell in 87% of those winters. The last 32°F night of spring typically comes 39 days after the last snow.

ZIP 37375 is under a mile from Sewanee, TN, which stands at 1,928 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 37375 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.