No U.S. state will be fully underwater by 2050, but several states will lose significant coastal land to regular flooding. Sea levels along the U.S. coastline are projected to rise 10 to 12 inches by 2050, matching the total rise measured over the entire last century in just three decades. That amount of rise won’t submerge entire states, but it will push the ocean permanently onto low-lying land, flood hundreds of thousands of homes, and reshape coastlines from Florida to Louisiana to New Jersey.
The real picture is less dramatic than a state disappearing and more serious than most people realize. Rather than a sudden submersion, the process looks like this: high tides start reaching farther inland, flooding that used to happen once a decade starts happening every year, and communities that were livable become unlivable. Researchers define a place as facing “chronic inundation” when floods hit at least 26 times per year, or roughly every other week. By 2050, nearly 400,000 U.S. homes could reach that threshold.
The States With the Most at Stake
Florida tops every risk list by a wide margin. An estimated 505,000 people and 355,000 homes sit in areas vulnerable to severe coastal flooding by 2050. Much of South Florida, including parts of Miami-Dade, Broward, and Palm Beach counties, sits on porous limestone just a few feet above current sea level. Unlike a city protected by seawalls, water in South Florida can rise up through the ground itself, making traditional flood defenses less effective.
New York ranks second, with roughly 445,000 people and 188,000 homes at risk. Coastal neighborhoods in Brooklyn, Queens, and Staten Island are particularly exposed, along with Long Island’s southern shore. New Jersey follows closely, with 324,000 people and 232,000 homes in flood-prone zones. The Jersey Shore and the low-lying areas around the Meadowlands and Delaware Bay face increasing tidal flooding that will worsen well before a major storm hits.
Louisiana is in a uniquely dangerous position, with 313,000 people and 140,000 homes at risk. The state isn’t just dealing with rising seas. Its land is actively sinking, a process called subsidence, caused by the compaction of Mississippi River delta sediments, groundwater withdrawal, and oil and gas extraction. Parts of coastal Louisiana are losing land to the Gulf of Mexico at a rate visible within a single lifetime. Communities that existed on maps 30 years ago are already gone.
Rounding out the top ten most affected states:
- Massachusetts: 174,000 people, 90,000 homes at risk
- Virginia: 146,000 people, 71,000 homes at risk
- California: 112,000 people, 46,000 homes at risk
- Texas: 78,000 people, 56,000 homes at risk
- North Carolina: 67,000 people, 50,000 homes at risk
- South Carolina: 67,000 people, 45,000 homes at risk
Why the Gulf and Atlantic Coasts Face Greater Risk
The flooding threat isn’t evenly distributed. The Atlantic and Gulf coasts face significantly higher risk than the Pacific coast, for three reasons. First, the terrain is flatter. A foot of sea level rise on Florida’s Gulf Coast can push water miles inland, while the same rise along California’s cliffed shoreline may only shift the waterline a few feet. Second, the Atlantic and Gulf coasts experience higher rates of land subsidence, meaning the ground is sinking while the water is rising, effectively doubling the problem. Third, the rate of sea level rise itself varies by region, with the Gulf and mid-Atlantic seeing some of the fastest increases.
The Chesapeake Bay region is a prime example. Norfolk, Virginia is one of the fastest-sinking cities on the East Coast, and the bay’s funnel shape amplifies tidal flooding. The Houston-Galveston area in Texas faces a similar combination of subsidence and rising seas, and some of the world’s largest ports, including Houston’s, are at risk of becoming inoperable by 2050 without major adaptation.
What “Underwater” Actually Looks Like
The shift from dry land to flooded land is gradual, not sudden. By 2050, moderate coastal flooding events, the kind that close roads, damage cars, and push water into ground-floor buildings, are expected to occur more than 10 times as often as they do today. That change happens even without hurricanes or heavy rain. Routine high tides will do what only storms do now.
For homeowners, the practical consequence hits before the water does. Insurance premiums climb. Mortgage lenders tighten requirements. Property values in chronically flooding areas drop. A joint analysis by Zillow and Climate Central estimated that by 2100, 2.5 million homes worth a combined $1.3 trillion could face chronic flooding if emissions remain high. The economic damage starts decades earlier, as buyers and lenders price in the risk.
Infrastructure takes a hit too. Roughly 300 U.S. energy facilities, including power plants, oil refineries, and natural gas infrastructure, currently sit on land at or below four feet of elevation. Ports, airports, bridges, and railways all face increased exposure to floodwater and erosion. A third of 55 major coastal sites in the U.S. will see what’s currently a once-in-a-century storm surge become a once-in-a-decade event by 2050.
Which Specific Areas Will Flood First
Within the most vulnerable states, certain areas will cross the chronic flooding threshold well before 2050. In Florida, the Keys and low-lying neighborhoods in Miami Beach already experience regular tidal flooding during king tides. Parts of New Orleans that sit below sea level depend entirely on pumps and levees. Barrier islands along the Carolinas and Gulf Coast are eroding rapidly, with some losing dozens of feet of shoreline per year.
In the mid-Atlantic, Annapolis, Maryland already floods roughly 50 days per year during high tides, a number that was in the single digits a few decades ago. Atlantic City, New Jersey and Charleston, South Carolina are on similar trajectories. These aren’t projections about 2050. They’re conditions that are worsening right now and will accelerate as sea levels continue rising.
On the Pacific coast, the risk is lower but not zero. San Francisco Bay’s shoreline communities, parts of San Diego, and low-lying areas near Long Beach face increasing flood exposure. However, the steeper terrain and lower subsidence rates along the West Coast mean far fewer people and homes are in the flood zone compared to the East and Gulf coasts.
What Drives the Variation in Projections
The 10 to 12 inch projection for 2050 is a national average, and it holds relatively steady regardless of how aggressively the world cuts emissions over the next few decades. That’s because the warming already locked into the climate system from past emissions guarantees a certain amount of ice melt and ocean expansion. The choices made now about emissions will determine what happens after 2050, particularly whether sea levels rise another one to two feet by 2100 or four feet or more.
Local conditions create wide variation around that average. A community dealing with three millimeters per year of land subsidence effectively experiences twice the sea level rise of a community on stable ground. Storm surge patterns, tidal ranges, ocean currents, and shoreline shape all influence how much flooding a given inch of sea level rise actually produces. That’s why two coastal towns at the same elevation can face very different futures.