At 03:00 GMT on Saturday, Irma had maximum sustained winds of 257km/h (160mph), the National Hurricane Center in the USA said.
Irma has been downgraded to a Category 3 hurricane, with sustained winds of 125 miles per hour, but it is expected to strengthen before reaching Florida, it added.
Another 125 emergency rescues were made in less than an hour Monday in Orange County, home to Orlando - an inland city where many coastal residents had evacuated to before the hurricane.
Senterfitt told a teleconference a large airborne relief operation was being prepared by the Air Force and Air National Guard to take help to the chain of islands, which are linked by a dramatic series of bridges and causeways from Key Largo nearly 100 miles (160 km) southwest to the picturesque town of Key West.
Irma has shown her strength, and it's the reason so many fear what is heading to Florida.
Though the tropical storm's eye is moving north-northwest, bands of high winds and heavy rain can extend outward for 415 miles.
Hurricane Irma has already cut a devastating path through the Caribbean and is on track to hit Florida on Sunday.
Hurricane Irma wasn't the only vortex that the southeastern USA had to worry about Sunday.
According to Florida's Division of Emergency Management some 5.6 million residents have been ordered to evacuate - almost a quarter of the state population.
Gusts of 70 mph are expected in Middle Georgia Monday afternoon and into the evening hours as the center circulation of the hurricane remnants moves northward. He still had power. "It's awful, what we saw", Scott said. "And then, I think we're OK, knock on wood".
The massive storm toppling trees, dumping torrential rain.and snapping power lines. leaving more than 2 and a half million homes and businesses without power.
Miami International Airport, one of the busiest in the country, halted passenger flights through at least on Monday.
"We know that we are ground zero for Hurricane Irma", Tampa Mayor Bob Buckhorn said at a Sunday morning news conference.
The first one was over the Florida Keys, which Irma hit as a Category 4 hurricane. It caused $15 billion in damage and was blamed for as many as 35 deaths in the U.S. Along with hurricane warnings and watches in Florida, the weather service placed tropical storm warnings for large parts of Alabama, Georgia and SC.
"Anyone who didn't heed the evacuation orders here in Miami Beach, it's time to bunker down", Van Dam said. "It's like being on a ship". About 6.3 million of the state's approximately 21 million residents have been asked to evacuate.
In July, the Post published a front-page story documenting how the Bay area is the most vulnerable region in the United States to flood and damage if a major hurricane ever scores a direct hit.