Police have opened a criminal investigation into the deaths, which come four days after the coastal US state was battered by category three winds of up to 130mph.
Three elderly residents at the Hollywood Hills Rehabilitation Centre were found dead at the home, while a further five died later in hospital or while they were on the way to be treated.
The victims ranged in age from 71 to 99. Authorities believe their deaths were heat-related after air conditioning at the home cut out.
FPL, the company that partly supplies power to the home, said it met with police chiefs long before the storm season to discuss locations that would be prioritised for power restoration.
The Hollywood centre was "not one of them" but a hospital across the road was, a spokesman said.
The nursing home's other residents have been evacuated and the building has been sealed off.