MIAMI — Ready or not, Florida found itself face to face with Hurricane Irma’s galloping winds and rains on Sunday, as evacuees and holdouts alike marked uneasy time in homes and shelters from the Keys to the Panhandle, tap-tapping their nearly dead cellphones for news they were frantic to hear but helpless to change.

The hurricane rammed ashore at Cudjoe Key before whirling on the state’s southwest and west coast on the first day of its sodden chug north, buckling two giant construction cranes in Miami and rotating others like clock hands, snacking on trees and power lines, and interrupting millions of lives.

An apocalyptic forecast had already forced one of the largest evacuations in American history. Now it was time to find out what the storm would do — and whether the heavily populated cities of Naples, Fort Myers, St. Petersburg and Tampa were prepared.

“Everybody has a plan until they get punched in the face,” Mayor Bob Buckhorn of Tampa said at a Sunday news conference, paraphrasing the boxer Mike Tyson. “Well, we’re about to get punched in the face.”