London, OH: what USGS's seismic model says
Under the seismic model IBC and ASCE 7 use for new construction, London is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, London ranks above 41% of the 4,875 cities in this dataset for seismic hazard - the 41th percentile.
How London compares
The raw figures: peak ground acceleration 0.065g, short-period spectral response 0.128g, 1-second spectral response 0.064g. Among 254 Ohio cities in this dataset, London ranks 177 for seismic hazard, the 30th percentile within the state. About 10,743 people live in London, Ohio.
Retrofit economics for London
Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Ohio. 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 London address.
More on how this number was built
The methodology guide covers exactly how USGS's public design-maps API produced London'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.