ORLANDO, Fla. — Bracing for hurricanes is almost a summer tradition here: the steady, clanking sound of wood banged to windows, the endless lines for bottled water and fuel, the pilgrimages to fortified shelters.

But Irma, which struck Florida’s coastline twice and then tore through the state with a fury, is anything but a run-of-the-mill hurricane. It was wider than the peninsula itself. There was hardly anywhere in the state to escape its blustery wrath.

Certainly not in the tiny islands of the Keys, which found themselves nearly under water on Sunday after Irma zeroed in on Cudjoe Key, Fla., just after 9 a.m.

Not in the shimmering high-rises of Miami, where hurricane winds partially knocked down two construction cranes. Not in and around the tourist havens of Orlando and Tampa, where theme parks were shuttered.

Even the most northern pockets in Tallahassee, the capital, and the small towns along the Florida-Georgia line, were cowering with the rest of the state for a thorough pummeling from tropical-force winds.

To try to escape Irma, Floridians scattered across the state on clogged interstates. They slept on cots inside high schools, on narrow beds in roadside motels, on friends’ couches and wherever they could reach on a tank of gas. The question for everyone was whether to go, and then where to go, to best outlast the winds.

Irma’s ruinous march was, for a while, aimed directly at South Florida, prompting much of the population, with memories of Hurricane Andrew and fresh scenes from Hurricane Harvey, to flee to the north and west. But by Saturday morning, the storm had shifted west. And suddenly, Naples, Fort Myers and Tampa, a collection of Gulf Coast cities particularly vulnerable to storm surge, found themselves in harm’s way. For days, that part of the state had been considered for some a safe haven; all of a sudden it was the bull’s eye.

“I feel like the storm is chasing us,” said Antonella Giannantonio, 51, who wasted no time last week packing her family, including her octogenarian parents, into two cars, then driving from North Miami Beach to Naples, then Tampa.

Wearing a Navy cap, Florida’s governor, Rick Scott, stood before a bank of microphones as the storm crept closer, sounding the alarm in brutally direct sound bites: Evacuate. Leave now. Get out. His plain-spoken words and Irma’s promise of devastation forced one of the largest evacuations this country has seen.

On Sunday, as Irma’s winds left millions of Floridians in the dark, Mr. Scott’s message was even more sobering, as if there might be little else to say: “Pray.”

In Key West, a place so vulnerable that the authorities had said to remain was the most foolhardy of moves, Richard Peter Matson stayed anyway, and slept little as Irma neared. Even with a Category 4 storm bearing down on his home, he defended his decision to stay put, despite what he described as a challenging night. “I kept tossing, turning,” said Mr. Matson, an 81-year-old artist. “Things kept smashing and banging,” he said.

When the winds moved on, the Key West holdout stepped outside to briefly inspect his street, now strewn with debris and branches, broken shutters and windows. He saw a downed cable and remembered the voices of friends who had warned him he’d be electrocuted if he stayed behind.

If there is an opposite of a storm-chaser, it would be Brian Plate, a Key West boat captain who spent the past few days on the run. Mr. Plate, 36, took a cat and a friend and hit the road at about 2:30 a.m. Thursday, headed for St. Petersburg, a seemingly safe 400 miles away. Two hours into the seven-hour ride, he was so tired that he pulled over to take a nap. He awoke the next morning to grim news: Irma, then a Category 5 storm, was now headed for St. Petersburg.

He hit the road again, and about eight hours later, pulled into a friend’s farm in Sale City, Ga., carrying 100 pounds of rice and beans, plenty of tortillas, a generator and a portable stove. He learned there that the storm is headed for Georgia, too — but he is done running.

“My nerves are completely shot,” he said, expressing worry for his friends who stayed “down there.”

After ramming Key West, Irma marched north on Sunday, eventually coming ashore again at Marco Island, Fla., near Naples, around 3:30 p.m. In Miami, which escaped a direct hit, the storm nonetheless intensified enough to make a solid five-story hotel vibrate. Rain fell hard, the wind howled, and the daytime sky grew dark. In many places, water made the pavement go away, flooding areas across South Florida, from Fort Lauderdale to Miami and Miami Beach.

Behind the Element hotel by the Miami International Airport, a lake overflowed, sending water into the parking lot and up to the sandbags protecting the lobby.

The guests were a mix of residents of surrounding neighborhoods, stranded airline passengers and crew, and cruise-ship travelers who were brought back to port early and left to ride out the storm. Among the crowd was Ana Matia, who lives in the Brickell neighborhood of Miami. She felt safe in her building, she said, but worried about being cut off with her daughter, Alejandra, 5, for days on end. So they decamped to the hotel. Ms. Matia had friends who fled west, only to hear about the storm’s trajectory and flee back east again.

Four days before Irma hit, the Stovall family left their Coconut Grove cottage for St. Petersburg to escape the worst of the storm. John and Colleen Stovall; their son, Chaille; and their two cats made the 270-mile journey.

Mrs. Stovall, 57, the producing artistic director of Shakespeare Miami, who also lived through Hurricane Andrew, rescued her grandmother’s silver, some jewelry and her own beloved 2nd edition of The Norton Shakespeare.

“We are feeling a little snakebit,” Mrs. Stovall, said while a crew worked furiously to cover the 80 windows of her brother-in-law’s three-story house in a historic St. Petersburg neighborhood, six blocks from the bay. “We are eating breakfast, and my brother-in-law says: ‘I have good news and bad news. The good news is, your house won’t be destroyed. The bad news is, it’s coming for us.’ ”

Before Irma, Randy Rogers and Chuck Anderson, retirees, neighbors and fishing buddies, were accustomed to taking their identical 22-foot Hurricane deck boats out on the Caloosahatchee River in Fort Myers in pursuit of sea trout, redfish and snook.

As Irma’s driving rain swept across the windows of the hotel where they took refuge on Sunday, the two men wondered what would be left of that life after the storm. Even if the water somehow spared their homes and boats, Mr. Rogers said, the wind probably would not.