Frost Dates for 48176 — Saline, Michigan

Half of springs at Saline Wwtp, MI see their last 32°F night by May 2; only one in ten is past it by April 17, and one in ten still has one after May 18. Planting tender crops after May 8 leaves a 30% risk of a frost on them, after May 12 20%, and after May 18 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 38% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 11 in half of years, as early as September 29 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 13 days later, around October 24; 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 181 days one year in ten and falls short of 141 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 11 days longer, to about May 13, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 27 and March 21.

July is the warmest month at Saline Wwtp, MI, averaging 85°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 55% of years.

Warmth for growing adds up to 2,678 growing degree days a year (base 50°F), more than at 69% of the 172 Michigan stations. 34% of them (901) have built up by the end of June, and July adds the most, 669.

The nearest other station, Ann Arbor Municipal Airport, MI, 4 miles northeast of Saline, has a last frost 6 days later (May 8), a first frost 7 days earlier (October 4), a season 13 days shorter.

The first measurable snow (0.1 inch or more) in Saline usually arrives around November 12, and the last of the season around April 16. Those are the middle dates across the winters of 1991–2020 at Ann Arbor SE, MI, 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 16 days after the last snow.

ZIP 48176 is under a mile from Saline Wwtp, MI, which stands at 750 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 48176 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.