CNN  — 

Power has been restored to parts of downtown Honolulu after heavy rain flooded the area, but many residents and businesses will remain without power through Tuesday, according to a statement from Hawaii Electric.

“Hawaiian Electric crews worked throughout the night to restore service to customers in downtown Honolulu and Chinatown and were able to repair one of three transformers damaged by flooding. As a result, power was restored this morning to six buildings, including the State Capitol, state office and city municipal buildings, district court, Central Pacific Bank and First Hawaiian Bank,” the statement said.

Relentless rain in Hawaii left parts of the state under the threat of “significant and life-threatening flooding,” the National Weather Service in Honolulu said Monday night, with some areas already tallying more than a foot of rain over a 48-hour span.

Sheets of drenching rain came down as low-lying roads pooled with water, forcing drivers to navigate the flooded roadways.

There was just too much water at one time, which led to flooding, says KGMB/KHNL reporter Lynn Kawano.

The Honolulu Fire Department (HFD) responded to 90 storm-related incidents between Monday and Tuesday morning after heavy rain flooded parts of Oahu.

According to a press release, most of the calls were for flooded houses, but they received reports of downed trees and power lines and blown-off roofs. Responders rescued 10 people, including five boys, from rushing water in streams.

Monday was the second-wettest day in the history of Honolulu, according to the NWS.

hawaii radar

Much of Oahu was hit by up to 2 inches of rain an hour Monday. Honolulu, picked up nearly 8, breaking the record for the wettest December day.

The western Hawaiian Islands of Kauai and Niihau will remain under a flood watch through early Wednesday.

The situation had improved in many areas by later Tuesday, with Oahu dropped from a flood watch.

“Periods of heavy rainfall are possible over Kauai County tonight as a weakening kona low pulls deep tropical moisture over the western end of the island chain,” the NWS says.

Low spots are subject to extreme runoff, which can clog bridges and culverts, exacerbating the already dangerous flooding. Landslides are also expected.

Gov. David Ige declared a state of emergency Monday due to the heavy rains, which he said were “anticipated to continue to cause flooding damage to public and private property.”

The declaration allows the use of funds “to support state and county efforts in providing quick and efficient relief of suffering, damage, and losses caused by flooding and other effects of heavy rains,” Ige said on Twitter.

The dayslong rain event had already left some communities saturated.

Nene Cabin on the Big Island topped the list at 14.07 inches in 48 hours as of Monday night. Keaumo, also on the Big Island, recorded 13.64 inches and Kula on Maui received 12.95 inches.

hawaii drought

While the rain is creating potentially hazardous conditions, it may also help Hawaii recover from a drought.

More than half of the state, 56%, is under some level of drought and half of Oahu was under severe drought as of November 30. An updated drought report is expected in the coming days.

The threat of flooding comes days after parts of Hawaii were under a blizzard warning over the weekend. High winds and winter weather were seen in mountain summits on the Big Island, the NWS said.

CNN’s Travis Caldwell, Jenn Selva, Kelly McCleary and Claudia Dominguez contributed to this report.