In a parting shot, it triggered severe flooding around Jacksonville in the state"s northeastern corner close to the Georgia line.
The storm surge brought some of the worst flooding ever seen there, with at least 46 people pulled from swamped homes.
Around the Tampa-St. Petersburg area, damage appeared relatively modest. Residents had braced for the first direct hit from a major hurricane since 1921.
But by the time Irma arrived in the middle of the night yesterday, its winds were down to 100 mph or less.
"When that sun came out this morning and the damage was minimal, it became a good day," said Tampa Mayor Bob Buckhorn. "What we thought was going to be a punch in the face was a glancing blow."