The U-S National Hurricane Centre says Florence is about to make landfall in North Carolina bringing with it life-threatening storm surges and hurricane force winds.
The Category 1 hurricane has top sustained winds of 150-kilometers per hour.
The slow moving, monster storm is expected to dump a significant amount of rain.
In one city, about 70 people had to be rescued from a hotel whose structural integrity was threatened by Hurricane Florence.
Officials found a basketball-sized hole in the hotel wall and other life-threatening damage, with some cinder blocks crumbling and parts of the roof collapsing.
None of the people rescued were injured.
The storm has knocked out power to more than 300,000 customers in North Carolina.