Tropical Storm Isaac is heading towards Cuba after causing flooding along the south coast of Haiti, where four people were killed.
The storm center is now east-southeast of Guantanamo Bay.
The BBC reports the government declared a state of alert in six provinces on Saturday and evacuated people from high-risk areas.
There were no immediate reports of major damage in Haiti, but heavy rain continued after the storm passed.
Some 400,000 people still living in tent cities since the earthquake in 2010 had to weather the storm under canvas.
Isaac is forecast to strengthen into a hurricane and reach the Florida Keys early on Monday. Governor Rick Scott on Saturday declared a state of emergency.