The same install spec does not work statewide. Lake-effect snow in the north and freeze-thaw along the Ohio River are different problems requiring different attachment.
Indiana looks like one market on a map. From an installation standpoint it behaves like three.
Northern Indiana, meaning the Lake Michigan shoreline and the corridor through South Bend, Mishawaka, and Elkhart, sits in the lake-effect snowbelt. The defining stress there is snow load and duration. Heavy sustained snowfall can begin before Thanksgiving and accumulate on rooflines for weeks. That changes two things about the install. The window compresses, so northern properties need to book on the early end of October rather than treating early October as optional. And attachment has to carry actual weight, because a run buried under accumulated snow is loaded very differently from one that is merely cold.
Central Indiana, the Indianapolis metro and the suburban corridor of Carmel, Fishers, Westfield, Zionsville, Noblesville, and Greenwood, runs a middle profile. Cold air, regular ice events, moderate snow totals, and frequent freeze-thaw cycling. Ice is the real adversary here more than snow depth. Ice adds weight and it works into any gap, and repeated freeze and thaw walks a marginal clip loose over a season. Clip density and wire routing get specified with that cycling in mind.
Southern Indiana and the Ohio River communities, from Columbus and Seymour down through Jeffersonville, New Albany, Evansville, and the river towns, are mildest on paper. Less snow, shorter cold stretches. But the freeze-thaw cycling is if anything more frequent, because temperatures cross the freezing point more often rather than staying below it. That is harder on attachment than a steady deep freeze. River communities also deal with humidity and fog off the water, which affects both summer install comfort and long-term corrosion on lower-grade hardware.
The practical consequences are worth stating plainly. There is no single statewide clip spec that is correct everywhere. A run specified for Evansville is under-built for Michigan City. A booking calendar that works for Jeffersonville leaves a northern Indiana property scrambling. And a permanent lighting system, which runs essentially uninterrupted year-round in central and southern Indiana, may occasionally be partially obscured during a heavy lake-effect event in the far north, which is a reasonable trade rather than a defect.
This is also why regional experience matters more than brand when choosing an installer. The question worth asking is not whether a contractor has done a lot of installs, but whether they have done them in your part of the state, through your winter. Indiana gives you three meaningfully different winters to get wrong.