Frost Dates for 38343 — Humboldt, Tennessee

Half of springs at Jackson 4 NE, TN see their last 32°F night by April 4; 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 17 days between the even-odds date and the one-in-ten date is narrower than at 34% of the 144 Tennessee stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 30 in half of years, as early as October 18 one year in ten, and holds off past November 13 one year in ten. A hard freeze of 28°F follows 9 days later, around November 8; in spring the one-in-ten date for 28°F is April 11, 10 days before the 32°F one. The freeze-free season lasts 208 days in a typical year, longer than at 61% of the 144 Tennessee stations; it reaches 230 days one year in ten and falls short of 188 one year in ten. On average 79 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 12 days longer, to about April 16, and return around October 22. Severe cold of 16°F or below comes in 97% of winters, usually between December 23 and February 12.

July is the warmest month at Jackson 4 NE, TN, averaging 90°F by day and 69°F at night; January is the coldest at 48°F and 28°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 63% of years.

Warmth for growing adds up to 4,765 growing degree days a year (base 50°F), more than at 82% of the 144 Tennessee stations. 39% of them (1,848) have built up by the end of June, and July adds the most, 922. Precipitation totals 55.1 inches a year, most in May (6.0") and least in August (3.5"); May to September bring 40% of it.

The nearest other station, Alamo 1 N, TN, 12 miles west of Humboldt, has a last frost 7 days earlier (March 28), a first frost 5 days later (November 4), a season 12 days longer.

The first measurable snow (0.1 inch or more) in Humboldt usually arrives around January 12, and the last of the season around February 16. Those are the middle dates across the winters of 1991–2020 at Jackson 4 NE, TN, 9.1 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 47 days after the last snow.

ZIP 38343 is 9 miles from Jackson 4 NE, TN, which stands at 430 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 38305 (Jackson). The 2023 USDA Plant Hardiness Zone Map lists ZIP 38343 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.