The Samoa Meteorology Service says the country should feel the worst effects of Cyclone Olaf early in the morning.
The Service Director, Mulipola Ausetalia, says the cyclone is currently around 140 kilometres north of Apia.
The centre of the cyclone is recording winds of 140 kilometres an hour, gusting to 240 kilometres an hour.
Mr Ausetalia says while Olaf's centre is likely to miss the Samoan islands, gale force winds and flooding of low-lying areas could still occur.
"A hurricane warning still remains for all of Samoa. About 1 am tomorrow morning it should be around 56 miles Northeast of Apia."
The Samoa Met Service Director, Mulipola Ausetalia.
The National Disaster Office says it this stage it expects Olaf to only cause agricultural damage.