Hurricane Irma made landfall at 9:10 a.m. Sunday on Cudjoe Key in the lower Florida Keys.
According to the National Hurricane Center, the Category 4 hurricane made landfall with maximum sustained winds of 130 mph.
Forecasters at the National Hurricane Center in Miami said Irma will remain a powerful major hurricane as the center of the storm moves over the Florida Keys and into southwest Florida.
Under the current forecast track, Irma is expected to pack catastrophic winds and life-threatening storm surge in the Keys and Florida's Gulf coast.
The worst storm surge is expected along the west coast of Florida once the center of Irma passes north.
Florida will be severely impacted by Irma with flooding rain, storm-surge flooding and damaging winds. In some parts of the state, along and east of the hurricane's path, damage could be catastrophic.
Although widespread wind damage isn't anticipated in South Florida, residents in the area can expect strong coastal inundation, flooding and tornadoes.
Wind gusts of more than 60 mph were reported in portions of Broward and Miami-Dade counties.
"The entire area of South Florida is covered in rain," Local 10 News chief certified meteorologist Betty Davis said. "These are all Irma rain bands."
Local 10 News hurricane specialist Max Mayfield said the tropical storm-force winds extend about 200 miles from the center of Irma.
"I don't think the really strong winds are going to get out of here until later tonight, that orange area right there, and the yellow, the tropical storm-force winds, that's going to be tomorrow morning," Mayfield said. "So, I hate to tell you that, but this is going to be all day and all night."
National Hurricane Center forecaster Dr. Mike Brennan said the storm surge could inundate the smaller islands of the Keys.
"The very worst of the storm surge is happening right now just to the right of where that eye made landfall," Brennan said.
He said water levels should rise in Key West as Irma makes its way north along the Gulf of Mexico.
"All that wind is pushing water right up against the southeast coast of Florida," Brennan said.
Brennan said to expect sustained tropical force-winds in Broward and Miami-Dade counties in the afternoon.
"It's going to be a really, really rough few hours," he said.
The last Category 4 storm to directly strike the Keys was Hurricane Donna in 1960.