Frost Dates for 40447 — Mc Kee, Kentucky

Half of springs at Heidelberg, KY see their last 32°F night by April 17; only one in ten is past it by March 31, and one in ten still has one after May 5. Planting tender crops after April 24 leaves a 30% risk of a frost on them, after April 30 20%, and after May 5 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 22 in half of years, as early as October 10 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 11 days later, around November 2; in spring the one-in-ten date for 28°F is April 22, 13 days before the 32°F one. The freeze-free season lasts 189 days in a typical year, shorter than at 63% of the 113 Kentucky stations; it reaches 209 days one year in ten and falls short of 166 one year in ten. On average 110 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 28, and return around October 14. Severe cold of 16°F or below comes every winter, usually between December 13 and February 27.

July is the warmest month at Heidelberg, KY, averaging 86°F by day and 65°F at night; January is the coldest at 44°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 87% of years and May still brings one in 16% of years.

Warmth for growing adds up to 3,849 growing degree days a year (base 50°F), fewer than at 61% of the 113 Kentucky stations. 37% of them (1,420) have built up by the end of June, and July adds the most, 793. Precipitation totals 49.7 inches a year, most in May (5.2") and least in November (3.0"); May to September bring 44% of it.

The nearest other station, Booneville 12SW, KY, 16 miles southeast of Mc Kee and 215 feet higher, has a last frost 7 days later (April 24), a first frost 3 days earlier (October 19), a season 11 days shorter.

The first measurable snow (0.1 inch or more) in Mc Kee usually arrives around December 25, and the last of the season around March 3. Those are the middle dates across the winters of 1991–2020 at Heidelberg, KY, 16 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 45 days after the last snow.

ZIP 40447 is 16 miles from Heidelberg, KY, which stands at 665 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 40447 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.