At least three people died in the storm, which came ashore in the same area hit by Frances three weeks ago. More than 1.5 million homes and businesses were without power.
By late afternoon, Jeanne had weakened to a tropical storm.
The devastating fourth punch to the state in just six weeks was an ordeal no state has endured since 1886, when Texas was the target. And the hurricane season still has two months to go.
Forget lightening striking twice, reports CBS News Correspondent Lee Cowen. Hurricanes are hitting here with the frequency of a pay check.
Insurance companies are torn between ruling each hurricane a separate event or lumping them together, saving victims costly deductibles.
"The last three weeks have been horrific," said mobile home park owner Joe Stawara. "And just when we start to turn the corner, this happens."
The hurricanes have prompted the largest relief effort in the Federal Emergency Management Agency's history, eclipsing responses for the 1994 earthquake in Northridge, California, and the 2001 terrorist attacks, director Michael Brown said.
"You're going to have some areas that have been hit once, twice and sometimes maybe three times," Brown said. "That's very frustrating, I know, for those who live in those communities."
Frances was larger, while Charley and Ivan were more powerful. But Jeanne was bad enough, once again sending the Sunshine State into a state of emergency.
Rain blew sideways, light poles fell and some bridges from the mainland to the Atlantic coast's barrier islands were flooded and impassable. Houses, condominiums and other buildings lost roofs, and a deserted community center in Jensen Beach was destroyed.
A mattress floated through a neighborhood in Vero Beach, where at least 1 foot of water rushed through some streets.
Gov. Jeb Bush sought to reassure weary Floridians. "This will become a memory," he said. "This does come to an end, and when it does we can probably use the term 'normal' again."
Seawater submerged the bottom floor of condominiums on Hutchinson Island, where Josh Lumberson rode out the storm. The parking lot was under 5 feet of sand and water, and sand rose to the kitchen cabinets inside first-floor condos. The ocean, once 75 yards away, lapped at the foundation.
"It sounded like the whole building was coming down," Lumberson said. "You could hear every metal screw coming out of the walls."
As the wind subsided, the clang of metal siding could still be heard on the barrier island.
Jeanne made landfall as a Category 3 hurricane with winds of up to 120 mph just before midnight Saturday at Hutchinson Island, 35 miles north of West Palm Beach. Frances struck in almost the same spot.
Once inland, Jeanne's 400-mile diameter system trudged across the state, passing northeast of Tampa. It then headed toward the Panhandle, where some 80,000 people were still without electricity because of Ivan, which struck 10 days earlier.
Max Mayfield, director of the National Hurricane Center in Miami, described the similar paths of Jeanne and Frances as perhaps unprecedented.
The toll from the latest storm extended as far north as Daytona Beach, where the famous beach was ravaged by erosion, and south to Miami, where one person was electrocuted after touching a downed power line.
Two people died when the SUV they were driving plunged into a lake beside the Sawgrass Expressway south of Boca Raton.
Jeanne's predecessors killed at least 70 people and caused billions of dollars in damage.
Single-engine planes flipped over at Palm Beach International Airport. At Cape Canaveral, the third hurricane to hit NASA's spaceport in just over a month blew out more panels and left more gaping holes in the massive shuttle assembly building.
More than 3,000 National Guard troops were also deployed to aid relief efforts.
Among the areas left without power were much of Palm Beach County, population 1.1 million, and - for the second time in three weeks - all of Vero Beach.
By 5 p.m., Jeanne had weakened to a tropical storm with maximum sustained winds of 65 mph and was expected to weaken further in the next 24 hours, the National Hurricane Center said. The center of the storm was located about 35 miles southeast of Cedar Key, Florida.
Earlier, Jeanne tore across the Bahamas, leaving some neighborhoods under 6 feet of water. The storm caused flooding in Haiti that killed more than 1,500 people.
Jeanne followed Charley, which struck Aug. 13 and devastated southwest Florida; Frances, which struck Labor Day weekend; and Ivan, which ravaged the western Panhandle when it made landfall in Alabama on Sept. 16.