Frost Dates for 49107 — Buchanan, Michigan

Half of springs at Niles, MI see their last 32°F night by April 27; only one in ten is past it by April 10, and one in ten still has one after May 14. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 9 20%, and after May 14 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 25 in half of years, as early as October 9 one year in ten, and holds off past November 7 one year in ten. A hard freeze of 28°F follows 12 days later, around November 6; in spring the one-in-ten date for 28°F is May 4, 10 days before the 32°F one. The freeze-free season lasts 180 days in a typical year, longer than at 95% of the 172 Michigan stations; it reaches 202 days one year in ten and falls short of 156 one year in ten. On average 124 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 11 days longer, to about May 8, and return around October 11. Severe cold of 16°F or below comes every winter, usually between December 10 and March 11.

July is the warmest month at Niles, MI, averaging 83°F by day and 61°F at night; January is the coldest at 33°F and 19°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 40% of years.

Warmth for growing adds up to 2,985 growing degree days a year (base 50°F), more than at 96% of the 172 Michigan stations. 34% of them (1,023) have built up by the end of June, and July adds the most, 693. Precipitation totals 41.5 inches a year, most in August (4.4") and least in February (2.3"); May to September bring 48% of it.

The nearest other station, South Bend Michiana Regional Airport, IN, 9 miles south of Buchanan, has a last frost 4 days later (May 1), a first frost 6 days earlier (October 19), a season 10 days shorter.

The first measurable snow (0.1 inch or more) in Buchanan usually arrives around November 17, and the last of the season around March 31. Those are the middle dates across the winters of 1991–2020 at Niles, MI, 6.1 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 27 days after the last snow.

ZIP 49107 is 6 miles from Niles, MI, which stands at 650 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 49120 (Niles). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49107 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.