Ian was downgraded to a tropical storm on Thursday morning, but the danger it posed was far from over.
According to the National Hurricane Center, the storm is expected to bring whipping winds, heavy rain and storm surge across Florida, Georgia and the Carolinas.
The hurricane will go down in history as tied for the fourth-strongest landfalling hurricane in the Sunshine State.
It made landfall as a Category 4 hurricane in southwestern Florida on Wednesday afternoon, including a 140-mile-per-hour gust recorded in Cape Coral.
Ian made landfall early Tuesday in Cuba's Pinar del Rio. It brought down the country's electrical grid and killed two people.
According to the National Hurricane Center, the tropical storm was located about 35 miles southwest of Cape Canaveral, Fla.
Maximum sustained winds were reported at 65 miles per hour.
Hurricane-force winds extend outward up to 40 miles from the center and tropical-storm-force winds reach outward up to 175 miles.
Ian was moving toward the northeast near 8 mph, with an increase in forward speed projected on Friday and Friday night.
Hurricane warnings have been changed to tropical storm warnings along the east and west coasts of the Florida peninsula.
Forecasters noted that the storm was still expected to produce intense winds, heavy rains and storm surge across parts of Florida, Georgia and the Carolinas.
It could be near hurricane strength when it approaches the coast of South Carolina on Friday.
The center will move farther inland across the Carolinas on Friday night and Saturday and weakening is expected.
FOX WEATHER: WHERE IS IAN HEADED NEXT? DANGEROUS STORM'S IMPACTS WILL BE WIDESPREAD
More than 2.5 million people in the Sunshine State were without power on Thursday morning, according to outage tracker PowerOutage.US.
Ian trapped people in flooded homes and damaged the roof of a hospital intensive care unit in Port Charlotte.
Staff were forced to evacuate the hospital's sickest patients to other floors.
In Fort Meyers, law enforcement officials received calls from people trapped in flooded homes, and pleas for aid were posted to social media.
No deaths were reported in the U.S. from Ian by late Wednesday evening.
However, a boat carrying Cuban migrants sank Wednesday in the waters of Key West.
The U.S. Coast Guard initiated a search and rescue mission for 23 people and managed to find three survivors about two miles south of the Florida Keys, officials said.
Four other Cubans swam to Stock Island, just east of Key West, the U.S. Border Patrol said. Air crews continued to search for possibly 20 remaining migrants.
Life-threatening storm surges and hurricane conditions were possible on Thursday and Friday along the coasts of northeast Florida, Georgia, and South Carolina, here Ian was expected to move inland.
The governors of South Carolina, North Carolina, Georgia and Virginia all preemptively declared states of emergency.
Ian became a hurricane early Monday morning.
The Associated Press contributed to this report.