Experts have warned Haiti could see the worst of the punishing winds from Hurricane Matthew.
The powerful Category 4 hurricane had winds of 145mph on Sunday evening. The US National Hurricane centre said its centre was expected to pass to the east of Jamaica and be very close to the south-western tip of Haiti late on Monday before reaching Cuba on Tuesday.
They said it was too soon to predict with certainty whether it would reach the US coast.
Matthew briefly reached Category 5, becoming the strongest hurricane in the region since Felix in 2007.
Forecasters said the southern Haitian countryside around Jeremie and Les Cayes could suffer most from the torrential rains and strong winds.
Officials with Haiti's civil protection agency said there were roughly 1,300 emergency shelters across the country, enough to hold up to 340,000 people.
In an address on Sunday carried on state radio, interim President Jocelerme Privert urged Haitians to listen closely to the warnings of officials and be ready to move.
"To those people living in houses that could collapse, it's necessary that you leave these houses to take refuge in schools and churches," he said.
Teams of civil protection officials walked the streets of Les Cayes and other areas urging residents to secure their homes, prepare emergency kits and warn their neighbours.
They also evacuated people from some outlying islands. Many Haitians appeared unaware of the looming hurricane.