The warnings followed a powerful earthquake with a magnitude of 7.7 that hit Canada's Pacific coastal province of British Columbia late on Saturday.
A tsunami warning prompted by a powerful earthquake off the Canadian coast sent at least 100,000 people fleeing from shore to higher ground in Hawaii late on Saturday, but an evacuation order was canceled after a series of weaker-than-expected waves rolled through the islands.
The warning was downgraded to an advisory – a lower-level alert – shortly after 1 a.m. Sunday (1100 GMT), though state civil defense authorities said beaches and harbors would remain closed for the time being, and residents were urged to stay away from the water.
There were no immediate reports of injuries, serious flooding or damage, but officials warned that abrupt changes in sea level and strong currents could still pose a hazard to swimmers and boaters.
"The threat may continue for several hours," the Pacific Tsunami Warning Center said in its alert.
While scientists had warned early on that waves as tall 6 feet (1.8 metres) could occur in places, tsunami wave activity was reported to have peaked at just 2.5 feet (0.8 metres) at the island of Maui shortly after 10:30 p.m.
"The tsunami arrived about when we expected it should," Senior Geophysicist Gerard Fryer told reporters at a news conference, saying: "I was expecting it to be a little bigger."
Tsunami warning sirens began blaring across the islands at about 8 p.m. as state officials ordered a coastal evacuation, prompting a mass exodus that clogged roadways as motorists fled low-lying areas.
As the forecast arrival time of the tsunami neared, Honolulu Mayor Peter Carlisle announced that all police and emergency personnel were being pulled out from potential flood zones, leaving anyone defying evacuation orders to fend for themselves. He also urged motorists who remained caught in harm's way due to gridlocked roads to abandon their vehicles and proceed on foot.