Frost Dates for 37755 — Helenwood, Tennessee

Half of springs at Oneida, TN see their last 32°F night by April 23; only one in ten is past it by April 6, and one in ten still has one after May 12. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 84% of the 144 Tennessee stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 18 in half of years, as early as October 5 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 9 days later, around October 27; in spring the one-in-ten date for 28°F is April 30, 12 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, shorter than at 97% of the 144 Tennessee stations; it reaches 198 days one year in ten and falls short of 155 one year in ten. On average 117 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 May 6, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 7 and March 2.

July is the warmest month at Oneida, TN, averaging 85°F by day and 64°F at night; January is the coldest at 45°F and 25°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 34% of years.

Warmth for growing adds up to 3,628 growing degree days a year (base 50°F), fewer than at 92% of the 144 Tennessee stations. 37% of them (1,333) have built up by the end of June, and July adds the most, 764. Precipitation totals 58.2 inches a year, most in December (6.0") and least in October (3.3"); May to September bring 41% of it.

The nearest other station, Stearns 2S, KY, 17 miles north of Helenwood and 220 feet lower, has a last frost 1 day later (April 24), the same first-frost date.

The first measurable snow (0.1 inch or more) in Helenwood usually arrives around January 10, and the last of the season around February 18. Those are the middle dates across the winters of 1991–2020 at Oneida, TN, 4.7 miles away: half of years saw snow earlier, half later. Snow fell in 64% of those winters. The last 32°F night of spring typically comes 64 days after the last snow.

ZIP 37755 is 5 miles from Oneida, TN, which stands at 1,440 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 37841 (Oneida). The 2023 USDA Plant Hardiness Zone Map lists ZIP 37755 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.