Frost Dates for 49751 — Johannesburg, Michigan

Half of springs at Atlanta 5 WNW, MI see their last 32°F night by May 11; only one in ten is past it by April 27, and one in ten still has one after May 31. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 24 20%, and after May 31 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 95% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 6 in half of years, as early as September 20 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 15 days later, around October 21; in spring the one-in-ten date for 28°F is May 14, 17 days before the 32°F one. The freeze-free season lasts 146 days in a typical year, shorter than at 71% of the 172 Michigan stations; it reaches 168 days one year in ten and falls short of 122 one year in ten. On average 170 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 17 days longer, to about May 28, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 26 and March 30.

July is the warmest month at Atlanta 5 WNW, MI, averaging 79°F by day and 57°F at night; January is the coldest at 24°F and 12°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 80% of years.

Warmth for growing adds up to 1,978 growing degree days a year (base 50°F), fewer than at 80% of the 172 Michigan stations. 30% of them (596) have built up by the end of June, and July adds the most, 552.

The nearest other station, Gaylord Otsego Co Airport, MI, 14 miles west of Johannesburg and 155 feet higher, has a last frost 11 days later (May 22), a first frost 6 days earlier (September 30), a season 16 days shorter.

The first measurable snow (0.1 inch or more) in Johannesburg usually arrives around November 1, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Vanderbilt 11ENE, MI, 14.3 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 28 days after the last snow.

ZIP 49751 is 11 miles from Atlanta 5 WNW, MI, which stands at 1,180 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 49756 (Lewiston). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49751 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.