Frost Dates for 48858 — Mt Pleasant, Michigan

Half of springs at Central Michigan Univ, MI see their last 32°F night by April 30; only one in ten is past it by April 17, and one in ten still has one after May 16. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 10 20%, and after May 16 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 38% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 20 in half of years, as early as October 5 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 14 days later, around November 3; in spring the one-in-ten date for 28°F is May 4, 12 days before the 32°F one. The freeze-free season lasts 171 days in a typical year, longer than at 78% of the 172 Michigan stations; it reaches 192 days one year in ten and falls short of 152 one year in ten. On average 147 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 10 days longer, to about May 10, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 4 and March 20.

July is the warmest month at Central Michigan Univ, MI, averaging 84°F by day and 61°F at night; January is the coldest at 30°F and 16°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 48% of years.

Warmth for growing adds up to 2,696 growing degree days a year (base 50°F), more than at 73% of the 172 Michigan stations. 32% of them (871) have built up by the end of June, and July adds the most, 688.

The nearest other station, Oil City 2S, MI, 10 miles east of Mt Pleasant, has a last frost 15 days later (May 15), a first frost 21 days earlier (September 29), a season 37 days shorter.

The first measurable snow (0.1 inch or more) in Mt Pleasant usually arrives around November 22, and the last of the season around April 7. Those are the middle dates across the winters of 1991–2020 at Alma, MI, 16.6 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 48858 is 2 miles from Central Michigan Univ, MI, which stands at 795 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 48858 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.