St. Petersburg, FL: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, St. Petersburg is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts St. Petersburg in the 6th percentile nationally for seismic hazard - higher than 6% of the 4,875 US cities USGS was checked against here.

St. Petersburg by the numbers

The raw figures: peak ground acceleration 0.023g, short-period spectral response 0.051g, 1-second spectral response 0.029g. Among 228 Florida cities in this dataset, St. Petersburg ranks 127 for seismic hazard, the 44th percentile within the state. About 267,102 people live in St. Petersburg, Florida.

Bracing and bolting: the actual cost

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

Earthquake insurance for a St. Petersburg home

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 St. Petersburg address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced St. Petersburg'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.