Power outages from Hurricane Irma in Florida and nearby states declined to about 6.9 million customers on Tuesday from a peak over 7.4 million late Monday as utilities organised one of the biggest restoration efforts in USA history.
Electricity company Florida Power & Light said on Monday it was doing final checks before bringing back nuclear reactors that were powered down as Hurricane Irma hit Florida.
Irma hit southwest Florida on Sunday morning as a unsafe Category 4 storm, the second-highest level on the five-step Saffir-Simpson scale.
After Hurricane Wilma knocked out power to millions of Floridians, FPL spent $3 billion over the past decade to bolster the power grid. "That restoration process will be measured in weeks, not days", said FPL spokesman Rob Gould at a news conference.
Most outages were in Florida Power & Light's service area in the southern and eastern parts of the state.
As the storm weakens as it heads toward Georgia, outages have leveled off or even declined at some Florida utilities, while increasing in Georgia, South Carolina and Alabama.
In Georgia, utilities reported over 1.1 million customers without power Tuesday, down from a peak of around 1.3 million on Monday night.
FPL said on Friday that Irma could affect around 4.1 million customers, but that was before the storm track shifted away from the eastern side of the state.
In Miami-Dade County, there were about 574,000 outages, according to the AP.
The utilities had thousands of workers - some from as far away as California - ready to help restore power once Irma's high winds pass their service areas.
Almost 4.5 million homes and businesses lost power in the storm that made landfall in the USA on Sunday, and utility officials say it will take weeks to restore electricity to everyone. FPL, the state's biggest power company, said its outages dipped below 2.9 million by Tuesday morning from a peak of over 3.6 million Monday morning. FPL reduced power at one reactor at the St. Lucie nuclear plant due to salt buildup in a switchyard from Irma.