Frost Dates for 49799 — Wolverine, Michigan

Half of springs at Vanderbilt 11ENE, MI see their last 32°F night by June 7; only one in ten is past it by May 23, and one in ten still has one after June 29. Planting tender crops after June 16 leaves a 30% risk of a frost on them, after June 22 20%, and after June 29 10%. The 22 days between the even-odds date and the one-in-ten date is wider than at 98% of the 172 Michigan stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by September 14 in half of years, as early as August 24 one year in ten, and holds off past September 30 one year in ten. A hard freeze of 28°F follows 15 days later, around September 29; in spring the one-in-ten date for 28°F is June 9, 20 days before the 32°F one. The freeze-free season lasts 95 days in a typical year, shorter than at 99% of the 172 Michigan stations; it reaches 120 days one year in ten and falls short of 64 one year in ten. On average 200 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between November 11 and April 15.

July is the warmest month at Vanderbilt 11ENE, MI, averaging 80°F by day and 51°F at night; January is the coldest at 26°F and 8°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 67% of years.

Warmth for growing adds up to 1,737 growing degree days a year (base 50°F), fewer than at 91% of the 172 Michigan stations. 32% of them (548) have built up by the end of June, and July adds the most, 484. Precipitation totals 32.5 inches a year, most in August (3.5") and least in February (1.5"); May to September bring 49% of it.

The nearest other station, Boyne Falls, MI, 17 miles southwest of Wolverine and 177 feet lower, has a last frost 15 days earlier (May 23), a first frost 19 days later (October 3), a season 38 days longer.

The first measurable snow (0.1 inch or more) in Wolverine usually arrives around November 1, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Vanderbilt 11ENE, MI, 10.4 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 55 days after the last snow.

ZIP 49799 is 10 miles from Vanderbilt 11ENE, MI, which stands at 905 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 49799 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.