Hurricane landfall rates

Hurricane Idalia makes it four seasons in a row with a major hurricane landfall. It gives us a chance to have a look at how major (Cat 3+) hurricane landfalling rates have changed in recent years in historical data. The rate landfall of Cat 3+ events from 1968-2023 (which spans equal lengths of cold and warm sea periods either side of 1995) is 0.52. We’re covering the “satellite era” here so hopefully fairly confident on numbers.

If we look at the current warm period post-1995, after the major hurricane landfalling drought of 2006-2016, the 1995-2016 landfalling rate was 0.46 – actually below the 1968-2023 long-term average. So much for the warm sea! However, since 2016, the 8 major landfalls in the following 8 years has bumped up post-1995 warm sea landfalling rate to 0.62 (and remember we’re not finished with 2023, obviously).

What’s more intriguing is if we assume that the landfalling drought is nothing but a fluke, then using the “non-drought” years after 1995 either side of 2006-2016, our landfalling rate of Cat 3+ storms since 1995 is bang on 1 per year (this is cherry-picking of course) does highlight how that freakish period of no landfalls could have influenced our views of risk at the time, especially if this quiet period was nothing more than good old good luck. Contrasting the last two bars on the right here highlights the uncertainty around landfall rates when seas are warm.