How to use it for Michigan
The calculator opens on Detroit. Pick the area nearest you from the list below the state: twelve Michigan stations, from Detroit and Ann Arbor to Grand Rapids, Muskegon, Traverse City, Alpena, Marquette and Sault Ste. Marie. Then enter tonight’s snow in inches, when it falls, any freezing rain, the morning temperature and wind, and whether your district is rural.
Two Michigans
Southeast Michigan gets most of its snow from passing storms: Detroit averages 45 inches a year, and about 6 inches in one day comes once a winter. West Michigan and the northern Lower Peninsula sit downwind of Lake Michigan: Grand Rapids averages about 78 inches, Muskegon 87 and Traverse City 101, and Marquette in the Upper Peninsula nearly 200. The same 6 inches that gives Detroit about a 50% chance gives Grand Rapids about 40% and Marquette about 20%, because crews there handle it every winter. The table below lists every Michigan area’s numbers.
Cold days
Many metro Detroit districts close at a wind chill around −20 °F, so for Detroit the calculator uses that rule; for the rest of the state it estimates one from the local winter lows, colder further north. A −5 °F morning with a 15 mph wind gives about a −26 °F wind chill: in Detroit that reads above 95%.
Snow days and the calendar
Michigan forgives the first 6 lost days, and lawmakers added relief after the 2025 ice storm and again in May 2026, for counties under that year’s storm and flooding emergency orders. A district that has already used its forgiven days is slower to call another, so set Snow days used honestly.
Check your district’s website or app, and your local TV station’s closings list, between 5 and 6:30 AM.
Detroit: the numbers the calculator uses
| Snow in an average year | 45 in (114 cm) |
|---|---|
| One-day snowfall reached about once a winter (the snow tolerance) | 6 in (15 cm) |
| Average winter low, December to February | 22 °F (−6 °C) |
| Climate station | Detroit Metro AP, MI, NOAA U.S. Climate Normals 1991–2020 |
| Headline outcome | Schools closed |
| Cold rule | metro Detroit districts (via WXYZ) use about −20 °F: Howell and Livonia cancel at a sustained −20 °F wind chill, and Chippewa Valley “typically” starts talking about closing there. |
Every Michigan area in the calculator
| Area | Snow a year | Snow tolerance | Winter low |
|---|---|---|---|
| Detroit | 45 in | 6 in | 22 °F |
| Saginaw | 49 in | 6 in | 19 °F |
| Lansing | 50 in | 5.5 in | 20 °F |
| Flint | 52 in | 6 in | 18 °F |
| Ann Arbor | 61 in | 6 in | 19 °F |
| Houghton Lake | 66 in | 6 in | 14 °F |
| Grand Rapids | 78 in | 7 in | 21 °F |
| Alpena | 78 in | 7 in | 14 °F |
| Muskegon | 87 in | 7 in | 23 °F |
| Traverse City | 101 in | 7.5 in | 17 °F |
| Sault Ste. Marie | 120 in | 7 in | 12 °F |
| Marquette | 197 in | 11.5 in | 9 °F |