TALLAHASSEE, Fla. - More than 170,000 homes and businesses in Florida have lost power and the center of Irma is about 90 miles southeast of Key West.
Florida Power and Light said on its website that more than half of those outages were in the Miami-Dade area, where about 600,000 people have been ordered to evacuate.
The company has said it expects millions of people to lose power, with some areas experiences prolonged outages.
The company said it has assembled the largest pre-storm workforce in U.S. history, with more than 16,000 people ready to respond.
The U.S. National Hurricane Center says wind gusts near hurricane strength have been recorded in the Florida Keys as the center of Irma moves closer to the state.
Forecasters said Saturday night that Marathon had reported a wind gust of 71 mph (114 kph) and sustained winds of 51 mph (82 kph). Irma is about 105 miles (170 kilometers) southeast of Key West.
It has winds of 125 mph (200 kph).
Tornadoes in area
Meteorologists say heavy rain squalls spawning tornadoes are hitting South Florida part of Hurricane Irma's leading edge.
The National Hurricane Center says a hurricane hunter airplane found Irma's winds dropped from 125 mph to 120 mph, but that's likely to soon increase again now that the center of the storm is over bathtub-warm water.
Hurricane force winds extend 70 miles (110 kilometers) out from the 30-mile (48-kilometer) wide storm eye.
Marathon International Airport recently reported a sustained wind of 48 mph (77 kilometers per hour) and a gust to 67 mph (108 kilometers per hour).
Governor gives warning
Florida Gov. Rick Scott told people earlier Saturday evening that now is the time to go.
He says this is the last chance they will have to make a good decision.
The governor says millions of people will see life-threatening winds and storm surge as Irma approaches the state.
At least 76,000 people are without power as Irma unleashes winds and rain on the state.
Scott said Saturday night that the outages expected to grow as Irma moves closer to the state.
He warned people that the storm is life-threatening.
President Donald Trump is also cautioning people in Irma's path to "get out of its way" and not worry about possessions.
Trump says property is replaceable but lives are not, and that safety must come first.
He says the nation is grieving for those who've been killed by the powerful storm, which spent the week churning its way across the Caribbean, leaving death and destruction in its wake. Hurricane Irma is forecast to hit Florida's southern coast at daybreak Sunday.
Trump says the U.S. is as prepared as it can be for a storm as monstrous as Irma.
Trump spoke at a weekend Cabinet meeting at the Camp David presidential retreat in Maryland. He posted a brief video of his remarks on Twitter.
More than 75,000 people have flocked to shelters in Florida to escape Hurricane Irma's potentially deadly winds and storm surge.
The state said Saturday that more than 400 shelters are open, mostly in schools, churches and community centers.
A hectic scene happened outside a minor league hockey arena in southwest Florida, where thousands of people were stuck in line. Some waited for more than five hours to get inside because only two doors were open.
When rain began falling heavily, more doors were open and the 8,400 seat Germain Arena quickly filled.