Frost Dates for 47129 — Clarksville, Indiana

Half of springs at Louisville Mcalpine, KY see their last 32°F night by March 31; only one in ten is past it by March 14, and one in ten still has one after April 14. Planting tender crops after April 5 leaves a 30% risk of a frost on them, after April 8 20%, and after April 14 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 89% of the 125 Indiana stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 9 in half of years, as early as October 31 one year in ten, and holds off past November 25 one year in ten. A hard freeze of 28°F follows 11 days later, around November 20; in spring the one-in-ten date for 28°F is April 2, 12 days before the 32°F one. The freeze-free season lasts 225 days in a typical year, the longest of the 125 Indiana stations; it reaches 245 days one year in ten and falls short of 204 one year in ten. On average 77 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 11, and return around November 1. Severe cold of 16°F or below comes in 98% of winters, usually between December 28 and February 8.

July is the warmest month at Louisville Mcalpine, KY, averaging 89°F by day and 70°F at night; January is the coldest at 43°F and 26°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 45% of years.

Warmth for growing adds up to 4,560 growing degree days a year (base 50°F), more than at 98% of the 125 Indiana stations. 38% of them (1,711) have built up by the end of June, and July adds the most, 908. Precipitation totals 48.0 inches a year, most in April (4.8") and least in August (3.3"); May to September bring 41% of it.

The nearest other station, Louisville Bowman Field, KY, 8 miles southeast of Clarksville, has a last frost 3 days later (April 3), a first frost 6 days earlier (November 3), a season 11 days shorter.

The first measurable snow (0.1 inch or more) in Clarksville usually arrives around December 7, and the last of the season around March 8. Those are the middle dates across the winters of 1991–2020 at Louisville International Airport, KY, 8.6 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 23 days after the last snow.

ZIP 47129 is 2 miles from Louisville Mcalpine, KY, which stands at 440 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 15 other ZIP codes share the station; its figures are presented in full for 47150 (New Albany). The 2023 USDA Plant Hardiness Zone Map lists ZIP 47129 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.