A tropical cyclone warning remains in force for Aitutaki and Mauke in the Cooks Islands while other parts of the southern Cooks group are being warned to expect strong winds.
At 0523 UTC Cyclone Arthur was around 250 kilometres north of Aitutaki and 450 kilometres north of Rarotonga.
At its centre Arthur has winds of around 110 kilometres an hour with occasional gusts to 140 kilometres an hour.
It is gradually turning to the south east and is slowly beginning to weaken.
Forecasters say Aitutaki, Mauke and nearby smaller islands can expect damaging gale force winds over the next 24 hours with rough to very rough seas and a damaging heavy swell.
The rest of the southern Cooks are warned that winds may increase to damaging gale force over the next day or so.