Frost Dates for 48141 — Inkster, Michigan

Half of springs at Detroit Metro Airport, MI see their last 32°F night by April 20; only one in ten is past it by April 6, and one in ten still has one after May 8. Planting tender crops after April 28 leaves a 30% risk of a frost on them, after May 2 20%, and after May 8 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 81% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 27 in half of years, as early as October 14 one year in ten, and holds off past November 9 one year in ten. A hard freeze of 28°F follows 11 days later, around November 7; in spring the one-in-ten date for 28°F is April 24, 14 days before the 32°F one. The freeze-free season lasts 188 days in a typical year, longer than at 97% of the 172 Michigan stations; it reaches 207 days one year in ten and falls short of 167 one year in ten. On average 120 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 12 days longer, to about May 2, and return around October 15. Severe cold of 16°F or below comes every winter, usually between December 10 and March 11.

July is the warmest month at Detroit Metro Airport, MI, averaging 84°F by day and 64°F at night; January is the coldest at 32°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 24% of years.

Warmth for growing adds up to 3,114 growing degree days a year (base 50°F), more than at 99% of the 172 Michigan stations. 33% of them (1,042) have built up by the end of June, and July adds the most, 746. Precipitation totals 34.4 inches a year, most in May (3.7") and least in February (2.1"); May to September bring 49% of it.

The nearest other station, Dearborn, MI, 4 miles northeast of Inkster, has a last frost 11 days later (May 1), a first frost 12 days earlier (October 15), a season 22 days shorter.

The first measurable snow (0.1 inch or more) in Inkster usually arrives around November 22, and the last of the season around April 7. Those are the middle dates across the winters of 1991–2020 at Detroit Metro Airport, MI, 4.3 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 13 days after the last snow.

ZIP 48141 is 4 miles from Detroit Metro Airport, MI, which stands at 631 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 48180 (Taylor). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48141 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.