Frost Dates for 48836 — Fowlerville, Michigan

Half of springs at Howell Wwtp, MI see their last 32°F night by May 4; only one in ten is past it by April 20, and one in ten still has one after May 21. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 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 7 in half of years, as early as September 27 one year in ten, and holds off past October 21 one year in ten. A hard freeze of 28°F follows 13 days later, around October 20; in spring the one-in-ten date for 28°F is May 11, 10 days before the 32°F one. The freeze-free season lasts 156 days in a typical year, shorter than at 55% of the 172 Michigan stations; it reaches 174 days one year in ten and falls short of 136 one year in ten. On average 154 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 16, and return around September 29. Severe cold of 16°F or below comes every winter, usually between November 26 and March 25.

July is the warmest month at Howell Wwtp, MI, averaging 83°F by day and 58°F at night; January is the coldest at 31°F and 14°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 2,543 growing degree days a year (base 50°F), more than at 56% of the 172 Michigan stations. 33% of them (841) have built up by the end of June, and July adds the most, 637. Precipitation totals 32.9 inches a year, most in June (3.7") and least in February (1.6"); May to September bring 52% of it.

The nearest other station, Hell, MI, 17 miles south of Fowlerville, has a last frost 4 days earlier (April 30), a first frost 7 days later (October 14), a season 10 days longer.

The first measurable snow (0.1 inch or more) in Fowlerville usually arrives around November 25, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Howell Wwtp, MI, 8.8 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 30 days after the last snow.

ZIP 48836 is 9 miles from Howell Wwtp, MI, which stands at 917 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 48843 (Howell). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48836 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.