Madison, WI: what USGS's seismic model says

Madison carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Madison sits at the 19th percentile for seismic hazard among 4,875 US cities.

Where Madison sits in Wisconsin

The raw figures: peak ground acceleration 0.036g, short-period spectral response 0.074g, 1-second spectral response 0.048g. Among 157 Wisconsin cities in this dataset, Madison ranks 51 for seismic hazard, the 68th percentile within the state. About 285,300 people live in Madison, Wisconsin.

Retrofit economics for Madison

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Wisconsin. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Madison address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Madison's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.