All four U.S. landfalling category 5 hurricanes were tropical storms 3 days before landfall

[Mike S]

This is an interesting factoid from Ken Graham.

 

[Kory]

Add to this list the two most costly hurricanes: Hurricane Katrina and Hurricane Harvey. Katrina attained hurricane status just 3 days prior to landfall. Hurricane Harvey...just 2 days prior.

 

[Mike S]

Add to this list the two most costly hurricanes: Hurricane Katrina and Hurricane Harvey. Katrina attained hurricane status just 3 days prior to landfall. Hurricane Harvey...just 2 days prior.

Charley was very close to making the list as well I believe. I think it was a hurricane for only 3 days abs rapidly intensifying just short of CAT5 by just a few miles per hour.