Frost Dates for 37801 — Maryville, Tennessee

Half of springs at Knoxville Mcghee Tyson Airport, TN see their last 32°F night by April 1; only one in ten is past it by March 14, and one in ten still has one after April 17. Planting tender crops after April 7 leaves a 30% risk of a frost on them, after April 12 20%, and after April 17 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 2 in half of years, as early as October 21 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 11 days later, around November 13; in spring the one-in-ten date for 28°F is April 5, 12 days before the 32°F one. The freeze-free season lasts 215 days in a typical year, longer than at 81% of the 144 Tennessee stations; it reaches 236 days one year in ten and falls short of 194 one year in ten. On average 67 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 14, and return around October 24. Severe cold of 16°F or below comes in 94% of winters, usually between January 2 and February 1.

July is the warmest month at Knoxville Mcghee Tyson Airport, TN, averaging 88°F by day and 69°F at night; January is the coldest at 48°F and 30°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 51% of years.

Warmth for growing adds up to 4,664 growing degree days a year (base 50°F), more than at 72% of the 144 Tennessee stations. 39% of them (1,810) have built up by the end of June, and July adds the most, 885. Precipitation totals 51.9 inches a year, most in July (5.3") and least in October (2.8"); May to September bring 40% of it.

The nearest other station, Lenoir City, TN, 13 miles northwest of Maryville and 177 feet lower, has a last frost 4 days later (April 5), a first frost 1 day earlier (November 1), a season 5 days shorter.

The first measurable snow (0.1 inch or more) in Maryville usually arrives around December 30, and the last of the season around February 22. Those are the middle dates across the winters of 1991–2020 at Knoxville Mcghee Tyson Airport, TN, 8.4 miles away: half of years saw snow earlier, half later. Snow fell in 96% of those winters. The last 32°F night of spring typically comes 38 days after the last snow.

ZIP 37801 is 8 miles from Knoxville Mcghee Tyson Airport, TN, which stands at 962 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 37922 (Knoxville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 37801 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.