Frost Dates for 49690 — Williamsburg, Michigan

Half of springs at Traverse City Cherry Cptl Airport, MI see their last 32°F night by May 12; only one in ten is past it by April 26, and one in ten still has one after May 27. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 22 20%, and after May 27 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 55% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 16 in half of years, as early as October 1 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 14 days later, around October 30; in spring the one-in-ten date for 28°F is May 16, 11 days before the 32°F one. The freeze-free season lasts 155 days in a typical year, shorter than at 58% of the 172 Michigan stations; it reaches 177 days one year in ten and falls short of 135 one year in ten. On average 149 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 25, and return around October 2. Severe cold of 16°F or below comes every winter, usually between December 5 and March 27.

July is the warmest month at Traverse City Cherry Cptl Airport, MI, averaging 81°F by day and 59°F at night; January is the coldest at 29°F and 17°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 78% of years.

Warmth for growing adds up to 2,441 growing degree days a year (base 50°F), fewer than at 51% of the 172 Michigan stations. 30% of them (734) have built up by the end of June, and July adds the most, 631. Precipitation totals 29.2 inches a year, most in October (3.6") and least in February (1.0"); May to September bring 50% of it.

The nearest other station, S Boardman 2W, MI, 10 miles southeast of Williamsburg and 428 feet higher, has a last frost 12 days later (May 24), a first frost 12 days earlier (October 4), a season 22 days shorter.

The first measurable snow (0.1 inch or more) in Williamsburg usually arrives around November 12, and the last of the season around April 15. Those are the middle dates across the winters of 1991–2020 at Traverse City Munson, MI, 11.2 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 27 days after the last snow.

ZIP 49690 is 8 miles from Traverse City Cherry Cptl Airport, MI, which stands at 618 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 49686 (Traverse City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49690 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.