Oahu’s population declined by 12,337 residents from July 1, 2020, to July 1, 2021, according to U.S. Census Bureau data released Thursday, continuing a trend that was hurried along by the COVID-19 pandemic.

The Census Bureau estimated Oahu’s population at 1,000,890 as of July 1, down 1.2%, from the year-earlier figure.

In releasing the population estimates and “components of change” for the nation’s 3,143 counties and other statistical areas, the Census Bureau noted that “fewer births, an aging population and increased mortality — intensified by the COVID-19 pandemic — contributed to a rise in natural decrease nationwide.”

In Hawaii, however, although the state Department of Health reported that COVID-19 claimed roughly 500 lives over the July-to-July period, the state still recorded more births than deaths. And Oahu led the way with a “natural” population increase of 1,468.

That helped soften a bit the pandemic’s effect on residents fleeing the state over the high cost of living and to seek more job opportunities, but not nearly enough to offset the exodus.

Oahu saw a net migration loss of 13,686 residents over the one-year period, the Census data shows. So, although net international migration added 652 residents to the island’s population, there was a net loss of 14,338 from people moving to the mainland.

The COVID-19 pandemic crippled Hawaii’s economy for most of the past two years, chiefly its critical tourism industry and the businesses that rely on it. Chief state economist Eugene Tian said that “since the U.S. economy recovered faster than Hawaii, more people may have moved to the mainland.”

Tian, who heads the state Department of Business, Economic Development and Tourism’s Research and Economic Analysis Division, added that the Census Bureau’s statistical model prior to the 2020 census historically underestimated the state’s population. With a new model in place, he said the population estimates may be revised later this year or early next year but that the trend of Hawaii’s head count decreasing every year since 2017 will stay true.

“I feel that we did have more people move to the mainland, but the magnitude may not be as high as the Census Bureau estimates,” Tian said.

Maui County’s population also declined over the 12- month period, by 434 residents to 164,221, down 0.3%, according to the latest Census Bureau data.

Hawaii and Kauai counties saw population increases during that time, likely due to housing affordability, especially on the Big Island, Tian said.

Hawaii County, the second most populous in the state, had an estimated 202,906 residents, an increase of 2,160, or 1.1%, according to Census data.

Kauai County saw its population grow by 253 residents to 73,454, an increase of 0.3%.

Census Bureau data released in December estimated the state’s total population at 1,441,553 as of July 1, down 0.7%, or 10,358 residents, from the July 1, 2020, figure. The total includes the 82 residents of Kalawao County, Molokai.

The state saw a natural population increase of 1,256 over the July-to-July period, which was well offset by a net migration loss of 11,526 residents, according to Census Bureau data. Although Hawaii added 1,077 residents in net international migration, the number of residents moving to or from the mainland showed a net loss of 12,603.

Tian said he expects the state’s population will continue to drop due to “our economic recovery falling behind the U.S.” and the increasingly high cost of living, especially housing prices.

Additionally, he said, it will take time for international in-migration to catch up with previous levels due to pandemic travel restrictions.

At the same time, natural population growth in the state will diminish, Tian explained.

“The natural growth is becoming smaller, because births have been declining and deaths have been increasing during the last 10 years in Hawaii,” he said. “In the next few years, there will be more deaths than births if the trend continues.”

Hawaii population estimates, July 1, 2020, to July 1, 2021

Total/Change/% change/Natural change / Net migration

State 1,441,553 -10,358 -0.7% 1,256 -11,526

Hawaii County 202,906 2,160 1.1% -310 2,471

Honolulu County 1,000,890 -12,337 -1.2% 1,468 -13,686

Kauai County 73,454 253 0.3% -40 281

Maui County 164,221 -434 -0.3% 138 -592

Note: Natural change is the net from births and deaths. State total includes 82 residents of Kalawao County.

Source: U.S. Census Bureau