Parts of the Florida Keys, the low-lying islands which bore the brunt of Hurricane Irma when the category-four storm struck on Sunday, are to re-open.
Entry is being restricted to residents and business owners as work continues to clear roads and check the state of bridges linking the islands.
Irma, which has since rapidly weakened, is being linked to 10 deaths in the United States.
Six people died in Florida, three in Georgia and one in South Carolina.
The storm also left a trail of destruction in the Caribbean, where at least 37 people were killed.
Both France and Britain have been criticised for not doing enough to help their nationals in overseas territories affected by the hurricane.
People with authorisation are being allowed into the towns of Key Largo, Tavernier and Islamorada from 07:00 (11:00 GMT), the authorities in Monroe Country said.
They were warned that services on the islands were limited: most areas were still without power and water, mobile phone signals were patchy and most petrol stations were still closed.
Teams were still working to clear Highway 1, the road connecting most of the inhabited islands, and bridge inspections were continuing.
Thousands of people are believed to have ignored calls to evacuate last week and clung on in the dangerously exposed islands during the storm.
After flying over the Keys on Monday, Florida Governor Rick Scott said he had seen "devastation".
"I just hope everybody survived," he said. "It's horrible what we saw. Especially for the Keys, it's going to be a long road.
"We saw a lot of boats washed ashore and we saw any, basically, any trailer park there overturned."
The US aircraft carrier Abraham Lincoln has arrived off Florida and other navy ships are due in the area on Tuesday to help distribute food to the Keys and evacuate residents,
However, Governor Scott added: "I didn't see the damage I thought I would see." Storm surges had turned out to be "not as bad as we thought", he said.
Other parts of the state escaped the storm lightly compared to the Caribbean islands.
"The storm surge flooding in Miami is a mere fraction of what would have happened if the core of the storm had been further east," Rick Knabb, former director of the National Hurricane Center, said in a tweet.
"We were spared the brunt of this storm," he said. "We came out much better than other parts of the state and we have to thank God for that."
Returning to her home in Miami's Little Haiti neighbourhood, evacuee Melida Hernandez, 67, found her home split down the middle by a tree.
"I wanted to cry, but this is what it is, this is life," she told Reuters news agency.
President Donald Trump has released emergency federal aid for Florida, describing the hurricane as a "big monster".
The storm was downgraded as it moved north towards Atlanta, Georgia, with maximum sustained winds of 35mph (56km/h) recorded, the National Hurricane Center (NHC) said in a statement.
Another hurricane, Jose, has been weakening over the western Atlantic, with swells due to affect parts of Hispaniola (the island split into Haiti and the Dominican Republic), the Bahamas, and the Turks and Caicos Islands, later this week.