Hurricane Irma is only the second storm on Earth - since satellites began tracking storms 40 years ago - to maintain raging 297 kilometre per hour winds for more than 24 hours.
This scientific fact about Irma comes from Colorado State University meteorology professor Phil Klotzbach and may go some way to dispel thoughts that Irma is being over-hyped.
Klotzbach says the other storm was typhoon Haiyan which hit the Phillipines in 2013 killing more than 6000 people.
"This thing is a buzzsaw," Klotzbach said, adding that he's glad Floridians are taking it seriously.
University of Miami hurricane researcher Brian McNoldy says Irma "could easily be the most costly storm in US history, which is saying a lot considering what just happened two weeks ago" in Texas.
