A high surf advisory for north- and west-facing shores of most islands is in effect until 6 p.m. today, according to the National Weather Service.
The advisory covers northern and western shores of Niihau, Kauai, and Oahu, and northern shores of Molokai and Maui.
Waves from 12 to 16 feet are expected along northern shores, and from 8 to 12 feet along western shores, forecasters said.
They said surf will be declining by late this afternoon.
Beach-goers should expect strong breaking waves, shore breaks, and currents which will make swimming dangerous.