A storm warning is in place for parts of Northern Cook Islands due to Tropical Cyclone Xavier.
The storm intensified into a category 1 cyclone on Sunday night.
The Cook Islands Meteorological Service says a storm warning is in force for Manihiki and Rakahanga, and the warning has been cancelled for Penrhyn.
Manihiki and Rakahanga can expect damaging gale-force winds up to 85km/h with wind gusts of up to 120km/h.
These are set to increase to 95km/h with gusts up to 130km/h later on Monday night.
Heavy rain and thunderstorms are also forecast.
The metservice is advising people to secure lose items around their homes and properties and for fishermen to avoid going out to the sea if conditions are unsafe.