A tropical storm warning continued Monday morning across Tampa Bay, meaning tropical storm-level winds with gusts up to 75 miles per hour between Apollo Beach and Ruskin.
Irma, which prompted one of the largest evacuations in USA history, was a Category 4 hurricane about 20 miles (30 km) east-southeast of Key West, Florida, as of 8 a.m. EDT (1200 GMT), the NHC reported. State media reported that people took shelter in tunnels, caves and official emergency shelters.
- Irma continues to weaken as it moves over northern Florida, the National Hurricane Center said. The storm could also produce isolated tornadoes in the Carolinas early next week. "This is an extremely risky and life-threatening situation".
Some 6.5 million people, about a third of the state's population, had been ordered to evacuate southern Florida.
On Wednesday, the eye of Irma passed over Barbuda, a tiny Caribbean island of about 1,800 people, destroying telecommunication systems and cell towers. By early Monday, almost 272,000 customers mostly in coastal and south Georgia were without power after Irma crossed over into the state overnight.
Hurricane Irma roared ashore in Florida for a second time, this time over Marco Island, near Naples on the Southwest Florida coast.
"Boy, are we happy to say, 'Goodbye Irma". The storm is expected to plow up the west coast of Florida by Sunday night.
"I was just riding the storm out, like many people here in Downtown Miami", said resident Gideon Ape, who heard the crane crack.
Lastly, there is a tropical wave to the west of the Cabo Verde Islands.
Irma is the first major hurricane to make a direct strike on Florida since Hurricane Wilma in 2005, and appears capable of a wider swath of destruction than each of the several storms that hit the state the mid-2000s.