(CNN) -- If predictions hold true, Florida may soon overtake New York as the nation's third-most populous state. Pointing to the states' growth rates, demographers say it's not a question of if, but when.
"If it doesn't happen this year -- it probably will -- but if not, probably next year," said Thomas Boswell, a University of Miami geography professor who studies population.
"It doesn't surprise demographers," Boswell said, "we have seen it coming for a long time."
On Monday, the U.S. Census Bureau releases its latest population estimates.
Stan Smith, population program director at the University of Florida's Bureau of Economic and Business Research (BEBR), agreed with Boswell that Florida likely will overtake New York at some point in 2014 or 2015.
From April 2010 to July 2012, Florida's population grew 2.7%, according to census data. In the same period, New York's grew 1%. The national average was 1.7%.
Last year's census estimate had the two states virtually neck and neck: New York's population was just under 19.6 million, only about 250,000 higher than Florida's.
"The really, really simple thing is that Florida and New York are growing, but Florida is growing faster," said Andrew Beveridge, a sociology professor at Queens College in New York.
While New York City and its surrounding suburbs, the Albany area, and Ithaca are all growing, much of upstate New York is experiencing declines in population, Beveridge said.
Manufacturing jobs have diminished in northern New York cities like Rochester, Buffalo and Syracuse. Florida, on the other hand, is seeing jump in tourism, real estate, construction, medicine and finance, Boswell said.
But immigration is also an important factor in explaining Florida's rise.
"Florida's growth for many years has been due primarily to migration," Smith said. "Typically, 80 to 90% of growth in the state has to do with people moving in."
The spike in immigration includes people moving from other states as well as from abroad, Smith said. Based on responses to BEBR surveys, Smith said, most people moving to Florida do so for job-related reasons. The state also draws retirees seeking a warmer climate.
If Florida surpasses New York in population, it likely will end up with more seats in the U.S. House of Representatives. In 2010, after the release of new census data, New York lost two seats and Florida gained two. Both states now have 27 House members.
California, with an estimated population of 38 million in 2012, and Texas (26 million) are the nation's two most populous states.