Gutters that face hail in July and ice dams in February

Two seasons on one roof edge

Ten years of monthly counts from NOAA's Storm Events Database show how the calendar splits:

Hail and thunderstorm events are logged by county, and winter events by forecast zone, so read the winter figures as a measure of how widely storms reached rather than a count of storms.

The county hail record, 2016-2025

These are hail events of 1 inch or larger in the database, with the largest stone recorded in each county during the window.

Dane County's 152 is the most of any Wisconsin county over the decade, with Waukesha second. In Michigan, Washtenaw's 33 trails only Marquette County's 42, and in Minnesota, Hennepin's 102 is second to St. Louis County's 146. What those strikes leave on aluminum and steel is the subject of the hail and gutters guide.

Snow and rain at the airports

Snowfall normals hint at the winter load along the eaves; precipitation normals, which include the water in that snow, show how much a gutter drains over a year. These are NOAA's 1991-2020 normals, and each snowfall figure links to the station's data file.

What the code requires at the eaves

The model International Residential Code handles ice dams at the roof, not the gutter. Section R905.1.2 requires an ice barrier in areas with a history of ice forming along the eaves and backing up water, as designated in the code's climate table. The barrier is at least two layers of underlayment cemented together, or a self-adhering polymer-modified bitumen sheet, running from the lowest roof edge to at least 24 inches inside the exterior wall line. States adopt their own versions of the code, so ask your local building department which one applies.

Ice dams, briefly

University of Minnesota Extension explains that ice dams form when snow sits on a roof whose upper surface is above freezing while the lower edge stays below it, and that the heat doing the melting comes mainly from the house. Gutters are where the result shows up. The National Weather Service office in Grand Rapids advises keeping gutters and downspouts clear so melting roof snow can drain, but a clean gutter does not fix the heat loss behind the dam. The ice dams guide explains the rest.

Roofers in Wisconsin and Michigan

Gutters hang on the roof edge, so when the eaves leak a roofer is a sensible first call. The National Roofing Directory lists roofing contractors in Milwaukee, Madison, Waukesha, Brookfield, Detroit, Grand Rapids, Ann Arbor and Troy.

You can also browse all Wisconsin roofing contractors or Michigan roofing contractors, and follow severe weather on the Wisconsin storm center and Michigan storm center. Local detail for southeastern Wisconsin is on the Milwaukee and Madison page.

Frequently asked questions

Which Wisconsin county gets the most large hail?

Dane County. NOAA's Storm Events Database records 152 hail events of 1 inch or larger there from 2016 through 2025, the most of any county in the state, followed by Waukesha County with 67.

Do gutters cause ice dams?

The University of Minnesota Extension traces ice dams to uneven roof temperatures driven mainly by heat escaping from the house, not to gutters. The National Weather Service in Grand Rapids still advises clearing gutters and downspouts so melting roof snow can drain.

Does the building code require ice and water protection at the eaves?

The International Residential Code requires an ice barrier where there is a history of ice forming along the eaves, extending at least 24 inches inside the exterior wall line. Your state's adopted code and local amendments control what applies to your house.

Which Upper Midwest city gets the most snow?

Among the airport stations listed here, Grand Rapids, with a 1991-2020 annual snowfall normal of 77.6 inches.