Frost Dates for 49236 — Clinton, Michigan

Half of springs at Tecumseh, MI see their last 32°F night by May 3; only one in ten is past it by April 20, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 12 20%, and after May 18 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 13 in half of years, as early as September 30 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 12 days later, around October 25; in spring the one-in-ten date for 28°F is May 7, 11 days before the 32°F one. The freeze-free season lasts 160 days in a typical year, longer than at 51% of the 172 Michigan stations; it reaches 180 days one year in ten and falls short of 141 one year in ten. On average 151 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 14, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 29 and March 20.

July is the warmest month at Tecumseh, MI, averaging 86°F by day and 59°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 59% of years.

Warmth for growing adds up to 2,734 growing degree days a year (base 50°F), more than at 78% of the 172 Michigan stations. 33% of them (893) have built up by the end of June, and July adds the most, 690.

The nearest other station, Manchester, MI, 7 miles northwest of Clinton and 185 feet higher, has a last frost 3 days earlier (April 30), a first frost 1 day later (October 14), a season 5 days longer.

The first measurable snow (0.1 inch or more) in Clinton usually arrives around December 3, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Tecumseh, MI, 4.7 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 50 days after the last snow.

ZIP 49236 is 5 miles from Tecumseh, MI, which stands at 780 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 49286 (Tecumseh). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49236 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.