There’s no such thing as a category 6 hurricane. Not just because having sustained winds over 174 mph isn’t possible, but as one of the creators of the Saffir-Simpson scale puts it, “… when you get up into winds in excess of 155 mph (249 km/h) you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it’s going to cause rupturing damages that are serious no matter how well it’s engineered.” So there’s no point in having a class of extra strong hurricanes in the same way the Tour de France has an Hors Catégorie for such mountain routes that would be difficult to cross via car let alone a bicycle.
It is true though that there is a concern with the changing climate that number of hurricanes, typhoons, willy-willys, etc. that can have the potential to reach Cat 5 status is growing or whatever might be its equivalent on their tropical cyclone scales.
