It can be easy to think of sea-level rise as a distant problem, something for future generations to worry about. But the reality is that the timeline is accelerating, and the maps of our coastlines are being redrawn within our lifetimes. By 2050, which is closer than it sounds, many of the coastal communities we know and love could look dramatically different. The combination of rising seas, more powerful storms, and land subsidence is creating a perfect storm for chronic flooding, putting homes, infrastructure, and entire historic neighborhoods at risk.
This isn’t just about a few more inches of water; it’s about a fundamental shift in where and how we can live safely along the water’s edge. The list of 10 US Cities That Could Be Partially Underwater by 2050 isn’t a work of science fiction—it’s a projection based on current climate data and elevation models. These are places with deep cultural and economic significance, facing a future where frequent flooding could become the norm, transforming daily life and the very landscape of the city.
Why Are These Cities at Such High Risk?
Several factors converge to make certain coastal areas more vulnerable than others. First, there’s the global phenomenon of thermal expansion (warmer water takes up more space) and melting land ice, which is pushing sea levels higher. But on a local level, the geology of the land plays a huge role. Many coastal cities, like New Orleans and parts of the Chesapeake Bay, are built on soft, sinking sediments, a process known as land subsidence. So, while the ocean is rising, the land is also sinking, effectively doubling the rate of relative sea-level rise. Add to that the increased frequency and intensity of storm surges from hurricanes and nor’easters, and you have a recipe for significant inundation.
10 US Cities That Could Be Partially Underwater by 2050
Based on projections from organizations like Climate Central and NOAA, here are ten American cities facing a particularly challenging future with sea-level rise. It’s important to remember that “partially underwater” often refers to areas that would be chronically flooded during high tides or vulnerable to permanent inundation, not necessarily that the entire city will be submerged.
New Orleans, Louisiana
Perhaps the most iconic example of a city below sea level, New Orleans is in a constant battle with water. Protected by a complex system of levees and pumps, the city remains incredibly vulnerable. With much of the city already sitting several feet below sea level and the surrounding wetlands—which act as a natural storm buffer—eroding rapidly, even moderate sea-level rise poses an existential threat.
Miami, Florida
Miami’s foundation of porous limestone is its greatest weakness. Water doesn’t just come over the sea walls; it seeps up from underneath the ground, a phenomenon often called “sunny day flooding.” This makes traditional sea walls largely ineffective. Combined with its low elevation and exposure to powerful hurricanes, Miami faces a future where routine life is regularly disrupted by water in the streets.
New York City, New York
Superstorm Sandy in 2012 gave New Yorkers a terrifying preview of what sea-level rise could mean for the city. Low-lying areas like Lower Manhattan, Brooklyn, and Queens are at extreme risk. The metropolitan area is investing in massive resiliency projects, but the scale of the challenge is immense, with vital infrastructure like subways and tunnels running perilously close to the rising water table.
Norfolk, Virginia
Home to the world’s largest naval base, Norfolk is one of the most vulnerable cities on the East Coast. The combination of sea-level rise and significant land subsidence means the water is rising here at a rate nearly twice the global average. Flooding is already a regular occurrence in many neighborhoods, threatening both military and civilian infrastructure.
Sacramento, California
While not a coastal city, Sacramento faces a unique water threat. Located at the confluence of the Sacramento and American Rivers, the city is protected by an aging system of levees. As sea levels rise in the San Francisco Bay, it pushes saltwater inland, putting pressure on the Delta levees. A major levee failure could put large parts of the city, which sits in a river basin, underwater.
Houston, Texas
Hurricane Harvey demonstrated Houston’s profound vulnerability to extreme rainfall and flooding. The city’s flat topography and extensive paving prevent water from being absorbed into the ground. As sea levels rise in the nearby Gulf of Mexico, the ability for floodwaters to drain out of the city is severely compromised, turning heavy rain events into catastrophic floods.
Charleston, South Carolina
This historic city is defined by its relationship with the water, but that relationship is becoming increasingly fraught. Charleston experiences frequent tidal flooding, and king tides now regularly swamp the Battery and other low-lying areas. The city’s beautiful historic district, built just feet above sea level, is on the front lines of this slow-moving crisis.
Boston, Massachusetts
Much of Boston’s downtown, including the Financial District and Faneuil Hall, was built on filled-in marshland. Now, that land is settling and the seas are rising. The city is proactively planning for a wetter future with initiatives like climate-resilient zoning, but its dense, low-lying urban core remains highly exposed to storm surges and regular flooding.
San Francisco, California
The San Francisco Bay Area might seem hilly and protected, but its shoreline is lined with vulnerable infrastructure. The San Francisco and Oakland airports, major highways, and Silicon Valley offices built on former wetlands are all at risk. Rising groundwater could also undermine building foundations and contaminate soil.
Tampa, Florida
Like Miami, Tampa’s flat landscape and location on Florida’s Gulf Coast make it a prime target for storm surges and sea-level rise. A direct hit from a major hurricane could be devastating, but the creeping threat of daily high-tide flooding is already impacting communities and could render some coastal properties uninsurable over time.
What Can Be Done to Mitigate the Risk?
While the situation is serious, it’s not hopeless. Cities are not standing still. Adaptation strategies are being implemented, ranging from hard engineering solutions like massive sea walls and levees to more natural approaches like restoring oyster reefs and mangrove forests that buffer wave action. “Managed retreat,” or the strategic relocation of people and infrastructure away from the most vulnerable areas, is also becoming a necessary, though difficult, conversation. On an individual level, understanding your own flood risk, supporting resilient infrastructure policies, and considering the long-term viability of coastal property investments are all crucial steps.
The future of these ten cities, and many others, is not yet written in stone—or water. The projections for 2050 serve as a powerful call to action. They highlight the urgent need for continued investment in climate resilience, thoughtful urban planning, and a global commitment to reducing the emissions that are driving this change. The choices we make today will directly shape the coastlines of tomorrow.