Ida was a tropical storm with winds near 45 mph when it came ashore near Mobile Bay in southern Alabama on Tuesday morning.
The tropical depression is moving northeast at about 9 mph and is expected to continue in that direction until being absorbed by a front Wednesday.
Forecasters say most of the heavy rain is over and tropical storm warnings have been discontinued.
The storm had shut down nearly a third of oil and natural gas production in gulf as oil companies evacuated workers ahead of Ida. Demand for energy is so low because of the economic downturn that energy prices have barely budged.
The National Weather Service is forecasting rain in the Augusta area after Ida's center made landfall this morning on Dauphin Island, Ala.
The National Hurricane Center expects the storm to cause heavy rainfall across Georgia.
Ida came ashore near Mobile Bay but by midmorning had weakened to a tropical depression as it lost strength and turned east from the Alabama Gulf Coast.
Richmond County is expected to get between 2 and 4 inches of rain Tuesday, according to the National Weather Service, with similar rainfall in Columbia County, North Augusta and Aiken.
A flash flood warning is in effect for Taliaferro, Warren and Wilkes counties through Wednesday morning.
The National Weather Service has issued a flash flood warning for north and central Georgia. Forecaster Kent McMullen said Tuesday that residents should expect from 3 to 5 inches of rain on Tuesday. He said some spots could be doused with up to 8 inches.
The downpour is expected to cause some creeks and streams to overflow. Mr. McMullen said the rain is expected to pass out of the state Wednesday.
Georgia and Alabama were plagued with deadly floods in September that killed at least 10 people. Weather experts say the flooding was near the top of the worst floods in the United States during the past century.
In Alabama, weather-hardened Gulf Coast residents rode out the rare late-season storm.
Forecasters said the storm had already spread most of its heavy rain onshore along the Gulf Coast ahead of Ida's center. Tropical storm warnings across Louisiana, Mississippi, Alabama and Florida have been called off.
Today's forecast in Augusta calls for a high of 66 degrees and a low of 57, with rain. Motorists are urged to be cautious because of low visibility and to slow down when approaching standing water in roads.