Frost Dates for 48815 — Clarksville, Michigan

Half of springs at Ionia 2SSW, MI see their last 32°F night by May 3; only one in ten is past it by April 17, and one in ten still has one after May 21. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 15 20%, and after May 21 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 81% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 12 in half of years, as early as September 29 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 15 days later, around October 27; in spring the one-in-ten date for 28°F is May 9, 12 days before the 32°F one. The freeze-free season lasts 161 days in a typical year, longer than at 56% of the 172 Michigan stations; it reaches 183 days one year in ten and falls short of 139 one year in ten. On average 148 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 13 days longer, to about May 16, and return around October 1. Severe cold of 16°F or below comes every winter, usually between December 2 and March 21.

July is the warmest month at Ionia 2SSW, MI, averaging 81°F by day and 60°F at night; January is the coldest at 29°F and 16°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 58% of years.

Warmth for growing adds up to 2,525 growing degree days a year (base 50°F), more than at 54% of the 172 Michigan stations. 33% of them (843) have built up by the end of June, and July adds the most, 639. Precipitation totals 36.0 inches a year, most in May (4.0") and least in February (1.7"); May to September bring 50% of it.

The nearest other station, Hastings, MI, 14 miles south of Clarksville, has the same 50% last-frost date, the same first-frost date, a season 3 days shorter.

The first measurable snow (0.1 inch or more) in Clarksville usually arrives around November 22, and the last of the season around March 27. Those are the middle dates across the winters of 1991–2020 at Lowell, MI, 7.6 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 37 days after the last snow.

ZIP 48815 is 12 miles from Ionia 2SSW, MI, which stands at 805 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 48846 (Ionia). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48815 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.