The National Weather Service says extremely hazardous high surf is expected on the northern and western shores of all islands beginning Sunday.
Northwest swells could reach between 35 and 55 feet, peaking on Sunday evening and slowly decreasing into Monday and Tuesday.
The Honolulu Department of Emergency Management urged residents and visitors to avoid the north and west shores during the high surf.
Those living along the shorelines should monitor the ocean conditions and get ready for any emergency.
If you're driving along the coastal roads, be aware that sand and seawater could suddenly wash across the roadways.
Maui Mayor Michael Victorino says officials are concerned about the possible combination of high surf and high tide. He says everyone should stay turned to news reports and be prepared.
The county plans to close the coastal campground at Papalaua Wayside Park off Honoapiilani Highway on Sunday as a precaution.