Florida governor Ron DeSantis on Monday urged residents to prepare for Hurricane Ian as it heads toward the U.S., expected to bring damaging winds, torrential rain and a powerful storm surge later in the week.

"Make sure you're prepared. There's no need to panic buy. If you normally don't drink a lot of water, you know, you may not need to go out and buy 20 gallons of water right now."

Despite the plea, residents across the state emptied store shelves of water and household items. Others filled sandbags as crews used chainsaws to trim palm trees ahead of the wind.

Schools and colleges in the Tampa area and northwest Florida canceled classes through at least Thursday.

The storm is expected to make landfall in Cuba on Monday evening before reaching the U.S. DeSantis warned residents should be prepared for potential evacuations as the storm nears.

The governor mobilized 5,000 members of the National Guard while an additional 2,000 are coming from Tennessee, Georgia and North Carolina with more troops on standby in other nearby states.

DeSantis also warned residents that there will be major power outages from the storm as winds were expected to knock down trees and utility poles.

Ian follows Hurricane Fiona, a powerful Category 4 storm that carved a path of destruction last week through Puerto Rico, leaving most of the U.S. territory without power and water before slamming into Atlantic Canada, where critical infrastructure might take months to repair.