Frost Dates for 40390 — Wilmore, Kentucky

Half of springs at Dix Dam, KY see their last 32°F night by April 7; only one in ten is past it by March 25, and one in ten still has one after April 24. Planting tender crops after April 15 leaves a 30% risk of a frost on them, after April 19 20%, and after April 24 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 47% of the 113 Kentucky stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 1 in half of years, as early as October 20 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 7 days later, around November 8; in spring the one-in-ten date for 28°F is April 11, 13 days before the 32°F one. The freeze-free season lasts 206 days in a typical year, longer than at 77% of the 113 Kentucky stations; it reaches 224 days one year in ten and falls short of 184 one year in ten. On average 80 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 14 days longer, to about April 21, and return around October 22. Severe cold of 16°F or below comes every winter, usually between December 11 and February 20.

July is the warmest month at Dix Dam, KY, averaging 86°F by day and 67°F at night; January is the coldest at 45°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 72% of years.

Warmth for growing adds up to 4,197 growing degree days a year (base 50°F), more than at 65% of the 113 Kentucky stations. 38% of them (1,610) have built up by the end of June, and July adds the most, 831. Precipitation totals 46.1 inches a year, most in May (4.9") and least in January (3.1"); May to September bring 45% of it.

The nearest other station, Lexington Bluegrass Airport, KY, 13 miles north of Wilmore, has a last frost 6 days later (April 13), a first frost 4 days earlier (October 28), a season 10 days shorter.

The first measurable snow (0.1 inch or more) in Wilmore usually arrives around December 26, and the last of the season around March 2. Those are the middle dates across the winters of 1991–2020 at Keene 1 WSW, KY, 5.7 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 36 days after the last snow.

ZIP 40390 is 6 miles from Dix Dam, KY, which stands at 870 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 40356 (Nicholasville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 40390 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.