Already a Category 2 storm, forecasters said Charley could develop into a major hurricane as it bore down on Cuba after drenching the Cayman Islands and killing a man in Jamaica.
Flanked by President Fidel Castro, meteorologist Jose Rubiera said on a live broadcast on state television early Friday that Charley had just made landfall on Cuba's main island on the southern coast near a town called Batibono.
In Florida, some 1 million people from the Florida Keys to Tampa Bay have been urged to evacuate.
"It does have the potential of devastating impact... This is a scary, scary thing," said Gov. Jeb Bush, who had declared a state of emergency.
Winds of 120 miles per hour, heavy rain and tornadoes are all likely when Charley comes ashore in Florida, a day after a less severe than expected assault from Tropical Storm Bonnie.
Bonnie, with winds of about 50 miles per hour, failed to produce any reported heavy rains or flooding, but the one-two punch of tropical storms is highly unusual. Storms have not struck so close together in Florida since 1906.
Residents braced for the worst as Charley made its way toward land, boarding up homes and buying supplies such as water, canned food and batteries. Beth Ciombor of Sarasota was at a Home Depot loading two sheets of plywood onto the top of her minivan, as her 2-year-old son watched.
"I'm on the verge of tears. It's so frightening," she said.
Charley is expected to pass west of the Keys early Friday before hitting Florida's western mainland, said Hugh Cobb, a meteorologist at the National Hurricane Center in Miami.
Storm surges also pose a serious threat; forecasters predict surges of up to 13 feet during high tide in Key West early Friday morning, Fort Myers late in the morning and Tampa Bay in the afternoon.
"This is a fairly sizable storm," Cobb said, with hurricane-force winds extending outward up to 30 miles from the center and tropical storm-force winds extending out 125 miles.
The evacuations included flood-prone sections of the Tampa-St. Petersburg area, along with MacDill Air Force Base on Tampa Bay. Only essential personnel will remain at the base, spokeswoman Lt. Erin Dorrance said. MacDill is home to U.S. Central Command, the nerve center of the war in Iraq.
"MacDill Air Force Base will probably be mostly underwater and parts of downtown Tampa could be underwater if we have a Category 3," said state meteorologist Ben Nelson. "In a Category 3, you can almost get to the point where Pinellas County becomes an island."
This is Florida's biggest evacuation request since 1999, when Hurricane Floyd brushed the state's east coast and prompted officials to urge a record 1.3 million to evacuate.
In the Panhandle town of Apalachicola, it looked as if nothing happened as Bonnie passed through the area. The sun was shining, the surf was calming, and by late afternoon Bonnie was downgraded to a tropical depression, centered about 30 miles northeast of Valdosta, Ga.
In the Keys, a steady line of traffic, marked by sport utility vehicles pulling boats on trailers, drove north along U.S. 1 on Thursday as visitors and mobile home residents followed orders to evacuate the entire 100-mile-long island chain.
Al Perkins, 55, a small business owner in Key West, placed office computers and a photocopier in garbage bags while a colleague hammered metal hurricane shutters over windows.
"If it gets over a 150 miles per hour winds, I'm outta here. Anything less than that, I've already been in, so it's not a problem," he said.
Charley was expected to remain at hurricane force when it passes over mainland Florida, but could move through central and north Florida before leaving the state, forecasters said. Four to 8 inches of rain were expected, with higher amounts possible, which could cause life-threatening flash floods and mud slides.
Gov. Jeb Bush earlier declared a state of emergency for all of Florida, and activated the Florida National Guard to prepare to respond to any damage. Red Cross workers were preparing to open shelters throughout the areas that could be affected.
"Our biggest concern is flooding and people being saved in the aftermath," Red Cross spokesman Peter Teahen said.
The Federal Aviation Administration said it had no reports of major airports on the mainland closing due to Bonnie or Charley.
Both storms could spread rain along the East Coast after hitting Florida, according to Hurricane Center projections. Heavy rain from the storms was forecast for North Carolina, just a week after Hurricane Alex damaged parts of that state's Outer Banks.
Bonnie and Charley are the second and third named storms of the Atlantic hurricane season, which runs from June 1 to Nov. 30.