Frost Dates for 48744 — Mayville, Michigan

Half of springs at Caro Wwtp, MI see their last 32°F night by May 7; only one in ten is past it by April 24, and one in ten still has one after May 24. Planting tender crops after May 15 leaves a 30% risk of a frost on them, after May 19 20%, and after May 24 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 62% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 9 in half of years, as early as September 25 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 14 days later, around October 23; in spring the one-in-ten date for 28°F is May 15, 9 days before the 32°F one. The freeze-free season lasts 154 days in a typical year, shorter than at 60% of the 172 Michigan stations; it reaches 175 days one year in ten and falls short of 133 one year in ten. On average 152 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 20, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 29 and March 25.

July is the warmest month at Caro Wwtp, MI, averaging 82°F by day and 60°F at night; January is the coldest at 29°F and 15°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 69% of years.

Warmth for growing adds up to 2,488 growing degree days a year (base 50°F), more than at 52% of the 172 Michigan stations. 32% of them (792) have built up by the end of June, and July adds the most, 643. Precipitation totals 34.3 inches a year, most in May (3.7") and least in February (1.6"); May to September bring 50% of it.

The nearest other station, Vassar, MI, 11 miles west of Mayville, has a last frost 2 days later (May 9), a first frost 2 days earlier (October 7), a season 4 days shorter.

The first measurable snow (0.1 inch or more) in Mayville usually arrives around November 25, and the last of the season around April 2. Those are the middle dates across the winters of 1991–2020 at Caro Wwtp, MI, 9.5 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 35 days after the last snow.

ZIP 48744 is 10 miles from Caro Wwtp, MI, which stands at 690 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 48723 (Caro). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48744 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.