Frost Dates for 49855 — Marquette, Michigan

Half of springs at Marquette, MI see their last 32°F night by May 8; only one in ten is past it by April 26, and one in ten still has one after May 23. Planting tender crops after May 15 leaves a 30% risk of a frost on them, after May 18 20%, and after May 23 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 12 days later, around November 2; in spring the one-in-ten date for 28°F is May 11, 12 days before the 32°F one. The freeze-free season lasts 164 days in a typical year, longer than at 65% of the 172 Michigan stations; it reaches 185 days one year in ten and falls short of 142 one year in ten. On average 153 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 15 days longer, to about May 23, and return around October 8. Severe cold of 16°F or below comes every winter, usually between November 28 and March 28.

August is the warmest month at Marquette, MI, averaging 74°F by day and 58°F at night; January is the coldest at 25°F and 12°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 75% of years.

Warmth for growing adds up to 1,776 growing degree days a year (base 50°F), fewer than at 89% of the 172 Michigan stations. 23% of them (408) have built up by the end of June, and August adds the most, 502. Precipitation totals 30.2 inches a year, most in October (3.4") and least in February (1.5"); May to September bring 49% of it.

The nearest other station, Marquette, MI, 6 miles west of Marquette and 746 feet higher, has a last frost 14 days later (May 22), a first frost 22 days earlier (September 29), a season 35 days shorter.

The first measurable snow (0.1 inch or more) in Marquette usually arrives around November 8, and the last of the season around April 17. Those are the middle dates across the winters of 1991–2020 at Marquette, MI, 2.1 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 21 days after the last snow.

ZIP 49855 is 2 miles from Marquette, MI, which stands at 665 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 49855 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.