Frost Dates for 49256 — Morenci, Michigan

Half of springs at Morenci, MI see their last 32°F night by May 4; only one in ten is past it by April 22, and one in ten still has one after May 19. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 14 20%, and after May 19 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 7 in half of years, as early as September 24 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 13 days later, around October 20; in spring the one-in-ten date for 28°F is May 9, 10 days before the 32°F one. The freeze-free season lasts 156 days in a typical year, shorter than at 55% of the 172 Michigan stations; it reaches 174 days one year in ten and falls short of 134 one year in ten. On average 148 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 14, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 25 and March 23.

July is the warmest month at Morenci, MI, averaging 86°F by day and 58°F at night; January is the coldest at 33°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 65% of years.

Warmth for growing adds up to 2,727 growing degree days a year (base 50°F), more than at 77% of the 172 Michigan stations. 34% of them (936) have built up by the end of June, and July adds the most, 674. Precipitation totals 38.1 inches a year, most in May (4.1") and least in January (2.3"); May to September bring 49% of it.

The nearest other station, Adrian Lenawee Co Airport, MI, 11 miles northeast of Morenci, has a last frost 7 days earlier (April 27), a first frost 13 days later (October 20), a season 17 days longer.

The first measurable snow (0.1 inch or more) in Morenci usually arrives around November 25, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Morenci, MI, 1.7 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 29 days after the last snow.

ZIP 49256 is 2 miles from Morenci, MI, which stands at 770 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 49247 (Hudson). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49256 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.