This National Oceanic and Atmospheric Administration (NOAA) satellite handout image shows tropical Hurricane Ian over Cuba, on September 27, 2022 at 11:51 UTC. (Photo: AFP)

Ian has strengthened into "an extremely dangerous" Category 4 hurricane and is expected to cause a life-threatening storm surge, catastrophic winds and flooding in the Florida Peninsula, the U.S. National Hurricane Center (NHC) said on Wednesday.