In a state already battered by Hurricane Helene two weeks ago, as many as two million people were ordered to evacuate, and millions more live in the projected path of the storm.
The utility with the most customers hit was Florida Power & Light Company, which has about 459,989 clients without power, followed by Duke Energy, which has 433,803 clients without power.
"Customers should be prepared for extended outages. The unprecedented storm's catastrophic conditions and recent heavy rain will likely cause significant damage and restoration challenges," said Florida Power & Light Company.
The company added that it has a restoration workforce of more than 17,000 people and has pre-positioned crews throughout the state.
Over 109,000 customers in Georgia and North Carolina were still without power in the aftermath of Hurricane Helen. Helene, which killed more than 200 people across six states, was the deadliest named storm to hit the mainland U.S. since Hurricane Katrina killed nearly 1,400 people in 2005.