A high surf warning is in effect through 6 p.m. Saturday for most islands.
Surf is expected to climb to 25 to 35 feet this afternoon, forecasters said today.
The warning covers north- and west-facing shores of Niihau, Kauai, Oahu, and Molokai, and northern shores of Maui.
“Anyone entering the water could face significant injury or death,” the warning said.
West-facing shores of the northern islands can expect up to 15- to 22-foot surf today.
In addition, a high surf advisory is in effect for western shores of Maui and the northern shores of the Big Island.
The swell is expected to gradually decrease Saturday, forecasters said.
Forecasters warn of strong longshore and rip currents, and waves occasionally making navigation in harbor channels dangerous.