Obama will travel to New Jersey on Sunday and tour some of the worst-hit spots in Paterson.
Flooding continues to be a problem in the city even as the region's rain-swollen rivers crest and slowly recede.
On Saturday, U.S. Rep. Frank Pallone Jr. announced that Obama had declared disaster areas in Monmouth and Middlesex counties.
The president had earlier declared a disaster in four other counties: Atlantic, Cape May, Cumberland and Salem.
The declaration frees up federal recovery funds to supplement state and local recovery efforts.
Irene killed seven people in New Jersey. About 5,000 homes were damaged by flooding.