Frost Dates for 38483 — Summertown, Tennessee

Half of springs at Mt Pleasant 1N, TN see their last 32°F night by April 5; only one in ten is past it by March 18, and one in ten still has one after April 21. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 16 20%, and after April 21 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 October 28 in half of years, as early as October 14 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 9 days later, around November 6; in spring the one-in-ten date for 28°F is April 12, 9 days before the 32°F one. The freeze-free season lasts 204 days in a typical year, shorter than at 47% of the 144 Tennessee stations; it reaches 227 days one year in ten and falls short of 181 one year in ten. On average 84 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 10 days longer, to about April 15, and return around October 20. Severe cold of 16°F or below comes in 98% of winters, usually between December 16 and February 12.

July is the warmest month at Mt Pleasant 1N, TN, averaging 91°F by day and 69°F at night; January is the coldest at 47°F and 27°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 66% of years.

Warmth for growing adds up to 4,789 growing degree days a year (base 50°F), more than at 85% of the 144 Tennessee stations. 40% of them (1,907) have built up by the end of June, and July adds the most, 925. Precipitation totals 62.3 inches a year, most in December (6.5") and least in October (3.9"); May to September bring 41% of it.

The nearest other station, Lawrenceburg Filt Plt, TN, 13 miles south of Summertown, has a last frost 3 days later (April 8), a first frost 3 days later (October 31).

The first measurable snow (0.1 inch or more) in Summertown usually arrives around January 16, and the last of the season around February 14. Those are the middle dates across the winters of 1991–2020 at Lawrenceburg Filt Plt, TN, 13.3 miles away: half of years saw snow earlier, half later. Snow fell in 71% of those winters. The last 32°F night of spring typically comes 50 days after the last snow.

ZIP 38483 is 11 miles from Mt Pleasant 1N, TN, which stands at 778 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 38474 (Mt Pleasant). The 2023 USDA Plant Hardiness Zone Map lists ZIP 38483 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.