State and federal emergency officials are still assessing the damage from the weeklong storm that caused at least 11 deaths in Florida and one each in Georgia and Alabama. More counties could be added.
The funding has not yet been extended to individual homeowners whose properties were damaged by high winds or flood waters.
"I'm pleased about the declaration and grateful to President Bush," Florida Gov. Charlie Crist said before touring flood damage at the St. Mark's River in north Florida.
Mary Blakeney, spokeswoman for the emergency management office in Okeechobee County, said officials hope to have a decision in coming days about individual home owner assistance.
"Those calls have been coming in ... and, at this point, we have some teams coming in that will be doing a more detailed assessment where they will be going into these homes and looking at what type of damage they've had," Blakeney said.
Fay was downgraded to a tropical depression on Saturday night after making a record fourth landfall in Florida. Its remnants were forecast to dump several inches of rain across Alabama, Mississippi, eastern Louisiana and Tennessee on Sunday and Monday.
Emergency officials in Alabama attributed another death to Fay on Sunday after recovering the body of a man who disappeared swimming in Lake Martin on Saturday during rough weather caused by the storm.
Authorities remain concerned about flooding in areas hit hard by the storm in central Florida. Brevard County Emergency Management spokeswoman Kimberly Prosser said waters on the St. John's River could continue to rise as runoff flows into the river.
Some of the areas expected to get heavy rains Sunday and Monday have been suffering long-term drought conditions.
In Huntsville, Ala., National Weather Service senior forecaster Andy Kula said the 5-day rainfall projection through Friday - 6 to 7 inches south of the Tennessee River and 3 to 4 inches north of the river - would spread out and was not expected to create a flood problem.
"We need something like this to recharge the soil. It probably won't be a total drought-buster," Kula said Sunday.
