Officials said there were no fatalities, but residents were urged to stay indoors because of the danger posed by downed power lines and uprooted trees.
"We have come through a really, really challenging night," the Royal Gazette quoted Wayne Caines, Bermuda's minister of national security, as saying.
Bermuda's Belco electric power company said 28,600 customers were without service because of the storm.
Humberto lashed the tiny British archipelago with hurricane force winds, blowing off some rooftops, before passing on late Wednesday, weather forecasters said.
The National Hurricane Center in Miami cautioned that coastal flooding was possible along Bermuda's coasts and warned that swells could create life-threatening surf and rip currents from Florida to North Carolina.
As of 0900 GMT, Humberto was 250 miles (400 kilometers) northeast of Bermuda, still a Category 3 hurricane with maximum sustained winds of 125 miles per hour (205 kilometers per hour).
But no coastal watches or warning remained in effect.