Atlantic hurricane seasons getting longer and broader

There’s an old saying in the Caribbean about hurricanes: June too soon, July stand by, August it must, September remember, October all over. But that has been blown out of the water (excuse the pun) by recent events in the US.

Hurricane Nicole (since downgraded to a tropical storm after making landfall as a Category 1 hurricane) hit the east coast of Florida on 10 November. It may have been considerably less destructive than hurricane Ian in September, but an Atlantic hurricane so late in the season is extremely unusual.

As modelling firm RMS pointed out, Nicole is only the second hurricane to make landfall along the east coast of Florida in the month of November since recordkeeping began. The other was in 1935. And broker BMS explained that only five named storms since 1851 have made landfall in the US after 5 November, all on the Florida Gulf Coast. Only one of those was a hurricane at the time of landfall.

But Nicole is not the only November Atlantic hurricane. Hurricane Lisa hit the coast of Belize (triggering a unique parametric cover protecting the Mesoamerican Reef) on 2 November. And hurricane Martin also became a Category 1 hurricane on 2 November.

The 2022 hurricane season (the season officially doesn’t end until 30 November, having started on 1 June) has been an average season with about 14 storms and eight hurricanes. But that hides a worrying trend, and not simply that the season appears to be expanding into November.

A study by Chaucer at the end of last year found that hurricanes and tropical storms are no longer the preserve of southern US states and Caribbean islands, with a shift northwards exposing locations outside of traditional storm hotspots. The study reveals that 16% of US and Caribbean hurricanes, tropical storms and tropical depressions are now hitting northern states, such as New York, New Jersey and the states of New England, compared to 12% 40 years ago.

There is a growing trend of hurricanes moving further north with greater ferocity, and increasing temperatures are making serious hurricanes even more severe. Chaucer said this will mean that locations outside of traditional storm hotspots are likely to be affected more often and, as a result, insurers must reconsider historical norms used to model risk.

And the global insurance industry is facing a long-run annual average loss of $106bn, compared to $75bn a year during the past decade, according to AIR Worldwide. The modeller said there is a greater than 40% chance the insurance industry will experience losses of more than $200bn in a single year during the next decade. It said insured losses will average about $66bn in North America.

But it is not just hurricanes. Secondary perils such as wildfires, tornadoes and severe thunderstorms are accounting for a larger share of the losses from catastrophe events than primary perils such as hurricanes.

Time perhaps for a new saying about hurricanes: May it may, June to November it definitely will, December probably all over.

As COP27, the 2022 United Nations Climate Change Conference, continues in Egypt, the broadening of the Atlantic hurricane season, both in terms of geography and timing, is just another example of why global action is needed on climate change.