The West Michigan Roofing Calendar: What to Check and Fix Each Month

For roof work, West Michigan's year splits into three parts rather than four. The working season runs roughly May through October, when normal highs in Grand Rapids sit between 60.7 and 83.1 degrees and normal snowfall is zero or close to it. The shoulder months, April and November, are workable but changeable. Winter, December through March, is when the roof is most likely to be under snow and when most repairs are leak response rather than planned work.

The numbers on this page come from the National Weather Service office in Grand Rapids, which publishes 1991 to 2020 normals compiled by NOAA's National Centers for Environmental Information. They include normal highs and lows, rain and melted snow, snowfall, and the average number of days at or below freezing each month. Those freezing-day counts matter more to a roof than the averages do, because sealants, adhesives and shingle seal strips all care about the temperature on the day of the work.

Two things the calendar does not change. An active leak is urgent in any month, because water in the deck and insulation keeps doing damage whether it is July or January. And thunderstorms stop roof work on the spot in any season. The National Weather Service is blunt about it: there is no safe place outside when thunderstorms are in the area, and you should wait 30 minutes after the last thunder before going back out.

March is still a winter month on a roof. Grand Rapids averages 7.6 inches of snow in March and about 23 nights at or below freezing, so the roof freezes and thaws almost every day. That cycling is hard on everything that seals the roof: it opens cracks in old pipe boots, works nails loose and pulls caulk away from flashing. April warms quickly, to a normal high of 57.8 degrees, with only 2.0 inches of snow but nearly 10 freezing nights and almost 4 inches of rain.

This is when winter damage becomes visible. Snow slides off and reveals missing or creased shingles, ice dams leave stains behind, and the first heavy spring rain finds whatever the winter opened up. It is also the start of the stormy part of the year. In March 2026, Michigan's insurance regulator issued storm guidance after deadly tornadoes touched down in Southwest Michigan, a reminder that severe weather does not always wait for summer.

July is the warmest month, with a normal Grand Rapids high of 83.1 degrees and about four days at 90 or above. August is close behind at 80.9. Heat is not usually what breaks a roof in Michigan, but a poorly ventilated attic can get very hot and age the shingles from below, and summer is a good time to notice it: a stuffy, hot upstairs and shingles that look worn on one side are both clues.

The bigger summer risk is storms. The National Weather Service in Grand Rapids found, in Southwest Michigan data from 1985 to 2021, that severe weather (large, damaging hail or damaging wind) occurs most often from June through September. Most roof damage from wind shows up as missing or creased shingles and lifted edges. Hail damage is harder to see from the ground and often needs a close look.

November is the turn. Grand Rapids averages a 47.2 degree high, 16 freezing nights and 7.1 inches of snow. December drops to a 36.1 degree high, about 26 freezing nights and 20.8 inches of snow, with the high staying at or below freezing on about 11 days. By the end of December the roof can be under snow until March.

Repairs keep happening, but the method changes. The Asphalt Roofing Manufacturers Association notes that shingles get less flexible as the temperature drops and can crack when bent, that the self-sealing strips need heat and sun to bond, and that in very cold weather shingles can be hand-sealed with an approved roofing cement to protect against wind. On flat and low-slope roofs, Mule-Hide's cold-weather guide says its cold-weather protocols apply at ambient temperatures of 40 degrees or lower, and its self-adhering EPDM membranes have minimum installation temperatures of 20 degrees (black) and 32 degrees (white), rising.

Planned work and leak response run on different clocks. If you have a list of small problems from a spring or fall inspection, it is worth fixing them together in one visit while the weather is good. If water is coming in, the month does not matter: stop the water first and plan the permanent repair for the next workable day.

At Stellar, standard repairs are scheduled every week for the following week, and nearly all are completed within two to three weeks year round. For a true emergency we are usually on site within 24 hours, weather permitting and if the roof is safe to access, and we come prepared to stop the water the same day.