Lee County, which encompasses Fort Myers, accounts for most of the fatalities.
The remnants of Ian are charging up the East Coast on Saturday after making landfall as a Category 1 hurricane in South Carolina on Friday afternoon.
The monster storm made its first U.S. landfall on Wednesday on Florida's west coast as a powerful Category 4 hurricane, shredding homes with ferocious winds topping 150 mph. Florida's death toll has climbed to at least 81, according to information from local officials.
Florida State University has canceled classes Tuesday through Friday as Hurricane Ian approaches.
"The cancellation of classes on Tuesday is to allow students to travel safely out of the area if they so choose," the university said. "Students who choose to stay in Tallahassee will be advised via the FSU Alert system to follow a 'shelter in place' protocol during the storm."
The St. Pete-Clearwater International Airport will close at 1 p.m. Tuesday due to the mandatory evacuation orders in Pinellas County. The airport will stay closed until the evacuation order is lifted.
Mandatory evacuation orders are in place for coastal parts of Hillsborough County, Florida. Over 300,000 people are expected to evacuate, officials announced Monday, with emergency shelters opening at 2 p.m. Monday.
Hillsborough County could face up to 15 feet of storm surge and 30 straight hours of tropical storm force winds, Florida Emergency Management Director Tim Dudley said.
County Administrator Bonnie Wise added, “We did not make this decision easily, but the storm poses a serious threat, and we must do everything we can protect our residents.”
Some residents of Sarasota County and Manatee County are also under mandatory evacuation orders.
-ABC News’ Alex Faul
Five-thousand members of the Florida National Guard have been activated to help during Hurricane Ian. Another 2,000 guardsmen from Tennessee, Georgia and North Carolina are also coming to help, Florida Gov. Ron DeSantis said.
Nearly 300 ambulances and support vehicles are being deployed to areas bracing for Ian’s landfall, DeSantis said.
-ABC News’ Alex Faul
