Hurricane Lane has been downgraded to a Category 2 storm as it approaches Hawaii, according to the US National Weather Service.
Maximum sustained winds are now near 110mph with higher gusts.
The service said some weakening is expected through Friday but the hurricane is expected to remain dangerous as it approaches Hawaii’s islands.
Hurricane warnings are in effect for the islands of Oahu, Maui, Lanai, Molokai and Kahoolawe - Hawaii’s Big Island has a tropical storm warning.
The service said Lane’s centre will move dangerously close to some Hawaiian islands later on Friday.
Police warned tourists to leave the world-famous Waikiki Beach after nearly 2ft of rain.
So far, about 1,500 people, mostly on Oahu, are in emergency shelters, said Brad Kieserman of the American Red Cross.
Emergency crews rescued five California tourists from a home they were renting in Hilo after a nearby gulch overflowed and flooded the house.
Suzanne Demerais said a tiny waterfall and small stream were flowing near the home when she arrived with four friends from the Los Angeles area, but the stream turned into a torrent, and the river rose rapidly over 24 hours.
Hawaii County firefighters, who were in touch with the home’s owner, decided to evacuate the house before the water rose any higher. They floated the five out on their backs, Demerais said.
Hurricane Lane lashed the Big Island with more than 30 inches of rain in about 24 hours. A wind gust of 67mph was recorded at Kohala Ranch on the northern side of the island.