New York and New Jersey were among the four northern states that started the Labor Day holiday weekend digging through debris left by the deadly deluge that killed more than 44 people and caused public transportation in New York City to grind to a halt.

Biden will visit storm-ravaged New Jersey and New York on Tuesday, just days after he travelled to hard-hit Louisiana where the storm made landfall almost a week ago.

The confirmed storm-related death toll in Louisiana rose to 12 on Saturday, Governor John Bel Edwards told a news conference.

He warned those numbers could increase because so many people are relying on power from generators, which were blamed for four carbon monoxide deaths among the 12 deaths.

More than 718,500 customers in Louisiana are still without power, down from the 1.1 million people that Hurricane Ida's devastation initially left in the dark.

Two new deaths in Louisiana were among evacuated nursing home residents at a Tangipahoa Parish warehouse now under state investigation after reports of squalid conditions.

"Sadly, we also can now confirm two additional deaths among nursing home residents who had been evacuated to the Tangipahoa facility," the Louisiana Department of Health tweeted on Saturday.

"This brings the death toll of nursing home residents evacuated to this facility to six," the health department tweeted.

Hot weather continues in the area nearly a week after Ida made landfall in Louisiana on Sunday as a Category 4 hurricane, downing trees, power lines and debris with wind gusts that reached 275km/h.

Amid the cleanup in the Northeast, commuters using public transportation to venture into their offices amid the COVID-19 pandemic may not be completely in the clear with Hurricane Larry intensifying as it churns about 1700 km east of the Leeward Islands.

Australian Associated Press