The National Weather Service has issued a high surf warning for the north and west-facing shores of Oahu, Molokai, Kauai and Niihau and the north shore of Maui because of potentially dangerous waves.
The high surf warning is in effect until 6 p.m. Monday.
Forecasters expect waves on north-facing shores to reach 18 to 22 feet this evening and up to 35 feet Sunday. West-facing shores are expected to see waves of 14 to 18 feet this evening and up to 25 feet Sunday.
The large northwest swell is expected to build from this afternoon through tonight.
Forecasters warn that large, battering waves will pound the shoreline. Swimming could be dangerous because of strong, and potentially deadly, rip currents.
Beachgoers are urged to stay out of the water and well away from the shore break.