Public Safety Secretary Frank Perry said National Guard soldiers, Highway Patrol troopers and Department of Transportation crews have been mobilized across the state.
The National Hurricane Center says data from an air force aircraft indicates that Hermine has strengthened to a hurricane, with maximum sustained winds increasing to near 75 mph (120 kph).
Hermine's upgrade from tropical storm makes it the fourth hurricane of 2016 in the Atlantic basin.
Florida Gov. Rick Scott says Tropical Storm Hermine (Her-MEEN) is potentially life-threatening, and he's urging Gulf Coast residents to take precautions immediately.
At a news conference Thursday, Scott said officials expect storm surges, flooding, power outages, high winds and downed trees when as the storm comes ashore.
City officials say that workers are clearing streets, drains and ditches in anticipation of heavy rains and high tides from Tropical Storm Hermine.
Scott ordered the closing of offices at noon Thursday due to the looming threat of Tropical Storm Hermine, which is expected to swell into a hurricane before slamming into the state's Panhandle.
The latest forecast Thursday morning had Hermine's top sustained winds at about 60 mph as it approached Florida's upper Gulf coast.
News outlets report high school football games in many areas will be played on Thursday night because Tropical Storm Hermine is expected to bring heavy rains to the state on Friday.
The National Weather Service in Wilmington, North Carolina, is warning residents to be prepared for heavy rains, possible flooding and perhaps even tornadoes as Tropical Storm Hermine heads toward the state from the Gulf of Mexico.
A tropical storm watch has been posted for a number of counties in southeastern North Carolina and a flash flood watch is in effect for Friday.
The Tallahassee Democrat (http://on.tdo.com/2c2jFxe) reports emergency management officials in Franklin County have issued a mandatory evacuation notice for people living on St. George Island, Dog Island, Alligator Point and Bald Point.
On the East Coast, a tropical storm warning has been issued for an area that extends from Marineland, Florida, northward to the South Santee River in South Carolina.
Florida's Gulf coast is bracing Thursday for a hit from Tropical Storm Hermine, which forecasters say could make landfall as a hurricane.
On the East Coast, a tropical storm warning has been issued for an area that extends from Marineland, Florida, northward to the South Santee River in South Carolina.