Frost Dates for 49862 — Munising, Michigan

Half of springs at Munising, MI see their last 32°F night by May 16; only one in ten is past it by May 1, and one in ten still has one after June 2. Planting tender crops after May 23 leaves a 30% risk of a frost on them, after May 27 20%, and after June 2 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 14 in half of years, as early as September 30 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 14 days later, around October 28; in spring the one-in-ten date for 28°F is May 20, 13 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 66% of the 172 Michigan stations; it reaches 169 days one year in ten and falls short of 128 one year in ten. On average 169 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 14 days longer, to about May 30, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 26 and April 2.

July is the warmest month at Munising, MI, averaging 73°F by day and 55°F at night; January is the coldest at 23°F and 11°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 90% of years and June still brings one in 13% of years.

Warmth for growing adds up to 1,497 growing degree days a year (base 50°F), fewer than at 98% of the 172 Michigan stations. 25% of them (380) have built up by the end of June, and July adds the most, 437. Precipitation totals 39.7 inches a year, most in October (4.9") and least in March (2.0"); May to September bring 43% of it.

The nearest other station, Ki Sawyer Wwtp, MI, 32 miles west of Munising and 436 feet higher, has a last frost 3 days earlier (May 13), a first frost 12 days earlier (October 2), a season 7 days shorter.

The first measurable snow (0.1 inch or more) in Munising usually arrives around November 5, and the last of the season around April 16. Those are the middle dates across the winters of 1991–2020 at Munising, MI, 3.3 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 30 days after the last snow.

ZIP 49862 is 3 miles from Munising, MI, which stands at 680 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 49862 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.