The National Hurricane Center says Irma has strengthened back into a Category 5 storm. Forecasters also extended hurricane and storm surge warnings and watches farther north in Florida.
The center says Irma made landfall on the Camaguey Archipelago of Cuba late Friday and has maximum sustained winds of 160 mph (260 kph).
The hurricane is about 300 miles (485 kilometers) from Miami and moving about 13 mph (20 kph) toward the west.
In the Gulf of Mexico, Hurricane Katia is making landfall north of Tecolutla, Mexico. Katia is still a Category 1 hurricane with winds of 75 mph (120 kph). Forecasters expect the hurricane to weaken quickly over the next 24 hours.
In the Atlantic, Hurricane Jose has almost hit Category 5 strength, with tops winds of 155 mph (250 kph). Jose is about 265 miles (430 kilometers) east-southeast of the northern Leeward Islands.
Florida has asked 5.6 million people to evacuate ahead of Hurricane Irma, or more than one quarter of the state's population, according to state emergency officials.
Andrew Sussman, the state's hurricane program manager, said Friday the total includes people throughout the southern half of the state as well as those living in inland Florida in substandard housing who were also told leave due to the dangerous storm that will slam the state this weekend.
Florida is the nation's third-largest state with nearly 21 million people according to the U.S. Census.
For days Gov. Rick Scott has been urging residents to evacuate, especially those who live in coastal areas that could be flooded due to the walls of water expected from Irma's arrival.
The National Hurricane Center is warning Floridians that even if the storm seems to moving away from the East Coast in the latest tracks, don't get complacent.
"This is a storm that will kill you if you don't get out of the way," said National Hurricane Center meteorologist and spokesman Dennis Feltgen.
Feltgen says the storm has a really wide eye, with hurricane-force winds that cover the entire Florida peninsula and potentially deadly storm surges on both coasts.
"Everybody's going to feel this one," Feltgen said.