Frost Dates for 40517 — Lexington, Kentucky

Half of springs at Lexington Bluegrass Airport, KY see their last 32°F night by April 13; only one in ten is past it by March 30, and one in ten still has one after May 1. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 25 20%, and after May 1 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 54% of the 113 Kentucky 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 16 one year in ten, and holds off past November 8 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 16, 15 days before the 32°F one. The freeze-free season lasts 196 days in a typical year, longer than at 55% of the 113 Kentucky stations; it reaches 217 days one year in ten and falls short of 175 one year in ten. On average 90 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 11 days longer, to about April 24, and return around October 19. Severe cold of 16°F or below comes every winter, usually between December 12 and February 26.

July is the warmest month at Lexington Bluegrass Airport, KY, averaging 87°F by day and 67°F at night; January is the coldest at 42°F and 25°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 83% of years and May still brings one in 11% of years.

Warmth for growing adds up to 4,093 growing degree days a year (base 50°F), more than at 58% of the 113 Kentucky stations. 37% of them (1,531) have built up by the end of June, and July adds the most, 828. Precipitation totals 49.8 inches a year, most in May (5.4") and least in January (3.4"); May to September bring 45% of it.

The nearest other station, Versailles 3 NNW, KY, 16 miles northwest of Lexington, has a last frost 1 day earlier (April 12), the same first-frost date, a season 2 days longer.

The first measurable snow (0.1 inch or more) in Lexington usually arrives around December 9, and the last of the season around March 9. Those are the middle dates across the winters of 1991–2020 at Lexington Bluegrass Airport, KY, 7.4 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 35 days after the last snow.

ZIP 40517 is 7 miles from Lexington Bluegrass Airport, KY, which stands at 980 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 14 other ZIP codes share the station; its figures are presented in full for 40324 (Georgetown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 40517 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.