Long Island population statistics: Latest U.S. Census Bureau data shows modest growth

Long Island posted modest population gains between 2023 and 2024, with the biggest drivers being international migration and births outpacing deaths, according to U.S. Census Bureau data released Thursday.

Both Nassau and Suffolk counties had population gains in the one-year period from July 1, 2023, to July 1, 2024, of nearly half a percent. Nassau’s 2024 population estimate was 1,392,438, up from 1,386,052 the year before — a gain of 6,386, or 0.46%. Suffolk’s 2024 population estimate was 1,535,909, up from 1,529,029 in 2023, a population increase of 6,880, or 0.45%, according to Newsday’s analysis of the data.

"I see it as a positive sign [for Long Island], comparing it with other regions throughout New York," said Jan Vink, a researcher with Cornell University’s Program on Applied Demographics, which published its analysis of those population estimates for New York State, not only for 2023 and 2024, but going back to 2020.

Fluctuating population

Vink said it "was expected to see some ups and downs," noting the COVID-19 pandemic years of 2020 and 2021 were particularly impactful.

"We see counties that lost population in the first two years," he said of the pandemic. "But they gained a lot in the second [two] years. Long Island was a little bit less impacted by all that volatile behavior."

Vink added: "In general, I think one of the messages we came across is that things have been pretty wild for the last couple of years. The story, for almost every county, has kind of a different path to get to the current number. It makes it harder to put a coherent story together."

The Cornell analysis found that the population of New York State "declined by 1.7% (336,524) since the 2020 census. However, the population increased in the most recent year (0.7% from July 1, 2023 to July 1, 2024)," by 129,881. 

Long Island was among three regions in the state that gained population since the April 1, 2020, decennial census, according to the Cornell analysis. The other regions that gained population in that time were Mid-Hudson and the Capital Region, the analysis showed.

It added: "The Capital Region, Long Island and Mid-Hudson saw mostly population gains over the last decade, with some [ups] and downs in recent years. It’s important to note that the estimate years (April 2020-July 2024) encompass major peaks in the COVID-19 pandemic, which had a large impact on New York City."

The report said New York City lost the most population between April 2020 and July 2022, a decrease of about 450,000, but had a rebound since 2022, gaining about 122,000.

A breakdown of data for Nassau and Suffolk shows both counties had losses from domestic migration, where people move out of the region to other communities within the state or country. Between 2023 and 2024, Suffolk saw a population decline of 6,469 in that regard while Nassau's fell by 4,425, according to Newsday’s analysis of the estimates. But both counties had gains in international migration, and more births than deaths, which the Census Bureau calls "natural increase."

International migration

Vink noted that the metropolitan New York City region saw a "big flow of [international] immigration migrants through those buses arriving in New York City" from Texas, primarily.

"Some of them moved to Long Island," he said.

Nassau had a natural population increase from 2023 to 2024 of 3,092, while Suffolk’s was 3,394, according to Newsday’s analysis of the estimates. Cornell’s analysis showed that from 2020 to 2024, Long Island had a natural population increase of 15,723, overtaking the Island’s net migration loss of 11,017.

The Census Bureau said in a news release: "The Population Estimates Program uses current data on births, deaths and migration to calculate population change." 

"Increasingly, population growth in metro areas is being shaped by international migration," Kristie Wilder, a demographer with the bureau’s Population Division, said in a statement.

"While births continue to contribute to overall growth," Wilder said, "rising net international migration is offsetting the ongoing net domestic outmigration we see in many of these areas."

The bureau’s statement added that "all of the nation’s 387 metro areas had positive net international migration between 2023 and 2024, and it accounted for nearly 2.7 million of the total population gain in metro areas — up from 2.2 million between 2022 and 2023."

The bureau said that just over 65% of the nation’s 3,144 counties made population gains last year: "In general, large counties had faster growth in 2024, while small counties noted more population loss."