On the centenary of the 18 September 1926 landfall of the Great Miami Hurricane there are warnings of the sheer scale of the costs should that event be repeated.

New analysis by Swiss Re Institute found just how much how the stakes have changed: a Category 5 hurricane striking the Miami or Tampa Bay area today could generate insured losses of $300 billion or more.

The reinsurer said the scenario illustrates how population growth and the accumulation of assets in exposed areas are driving higher insured natural catastrophe losses globally.

Balz Grollimund, head Catastrophe Perils at Swiss Re, said: “The Atlantic hurricane season has been relatively quiet so far this year, but it only takes one major storm making landfall in a highly exposed area to turn a quiet season into a costly one. One hundred years after the Great Miami Hurricane, the question is not simply how powerful the next major hurricane will be, but what it will encounter when it reaches shore. That lesson extends well beyond Florida: as populations and asset values increase in areas exposed to natural catastrophes, so does the potential for large insured losses.”

The report said a century of population and property growth has transformed the potential impact of a hurricane striking Miami-Dade County. Just over 100,000 residents lived there when the Great Miami Hurricane arrived in 1926, compared with around 2.8 million in Miami-Dade today. More than two million homes in the Miami metropolitan area, with a combined reconstruction cost exceeding $600 billion, are now at moderate or greater risk of hurricane wind damage.

“Where a hurricane makes landfall is critical,” Swiss Re explained. “Hurricane Andrew struck around 20 miles south of Miami as a Category 5 storm in 1992, largely sparing Miami’s much larger concentration of insured property. Swiss Re Institute estimates that the same track today would cause close to $100 billion in insured losses. By contrast, a Category 5 hurricane striking Miami or Tampa Bay could cause insured losses of  $300 billion or more.”

The report added the centenary is also a resilience story. Traditional and alternative reinsurance capacity can be more effective when supported by catastrophe modelling, disciplined accumulation management and effective mitigation. Stronger building codes and wind-resistant construction can help reduce hurricane losses. Updated standards helped newer homes in Florida withstand Hurricane Ian in 2022, while replaced and storm-proofed roofs further reduced vulnerability.

Monica Ningen, CEO US P&C Reinsurance at Swiss Re, said: “Florida’s growth has transformed the risk landscape, making it increasingly important for insurers, communities and policymakers to understand how exposure is changing. Stronger building standards have improved resilience, but continued population and property growth in exposed areas means the potential for severe losses remains significant. Effective mitigation and risk modelling can help manage that risk, while reinsurance helps insurers absorb the volatility of severe events.”