“Until you go through something like this, you just don’t know,” said Daniel Rossler, who rode out the storm in a concrete building in Tavernier Key with his wife. “I love it here. But I might leave to go to some other part of the country. I just don’t know.”

Mr. Rossler arrived from Chicago 22 years ago and works in construction, chasing the sun, the sand and the cocktails. “Everyone that lives down here wants to be off the mainland,” he said.

The Keys are happy to take them. Though it has been a destination for runaways from the continent it dangles from for centuries — when there was easy money to be made in shipwreck salvaging, and even before that — development has brought steady growth to the archipelago in recent decades. Some people come to get off the grid, camping in the mangrove forests or living on sailboats. More wealthy people are claiming real estate in Key West, the island most beloved of tourists, of Ernest Hemingway and of spring breakers, pushing up rents for the rest.

On Tuesday, the billboards on the way south on the Overseas Highway, which links the Keys to each other and to the mainland, stood ripped up by the wind. What remained of one of them read: “Come as you are.”

“The problem is, it’s one of those places that’s too beautiful for its own good,” said Carl Hiaasen, the author of many canonical Florida books and a former Keys resident. “The rational part of your brain is telling you this is probably not an ideal place to be in August and September, but the romantic part of your brain is saying, ‘God, it’s gorgeous — let’s go sit on the beach.’”

Longtimers become veteran readers of the meteorologist’s report. The lead-up to a big storm is powered by practicalities as much as fear, Mr. Hiaasen said. The commercial fishermen where he used to live would tie their boats in the mangrove forest to protect them from the storm. Even those who evacuated tended not to go far, hoping to be among the first to come back.