The National Oceanic and Atmospheric Administration expects five to eight named tropical cyclones in the region from June 1 through Nov. 30.
NOAA's Central Pacific Hurricane Center director Chris Brenchley also said Wednesday that El Nino conditions will boost water temperatures and contribute to storm activity.
NOAA predicts wind shear - which often breaks apart storms - will be weaker than normal.
There were six named tropical storms in the region in 2018. All became hurricanes.
Category 5 Hurricane Lane threatened Oahu in August before veering away from the island and weakening.