Extreme Weather Toolkit: Coastal Flooding

The frequency of coastal floods has risen sharply in recent decades. Rising sea levels due to human-caused warming will continue to increase both tidal flooding and flooding from extreme weather events in the years ahead.

The oceans absorb 90% of the extra heat caused by carbon pollution. As oceans heat up, the volume of seawater expands — causing sea levels to rise. Melting glaciers and ice sheets also contribute to rising sea levels. 

Global mean sea level rose 7.8 inches from 1901 to 2018, according to the latest IPCC reports. Sea levels have been rising faster since the late 1960s, and human activities are the primary cause. 

Sea level rise is accelerating along U.S. coasts. According to NOAA, sea levels along U.S. coasts are expected to rise as much over the next 30 years (10-12 inches, on average) as they did over the last 100 years. 

As sea levels rise, flooding is becoming more common along U.S. coasts, where 29% of the population lives.

In our warming climate, it no longer takes a strong storm to flood streets, homes, businesses, and ecosystems along the coast.  High tide flooding — also called nuisance flooding or sunny day flooding — is becoming more common in the U.S.

The annual frequency of U.S. high tide flooding has more than doubled since 2000. Flood frequency is projected to more than triple again by 2050 (relative to 2020) to reach a national average of 45 to 85 flood days per year.

Updated: April 2024

Resources

These resources explore the science, trends, and local impacts of coastal flooding and sea level rise

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Report

Rising Seas Stretch Risk Zones

As seas rise, land once safely above the tideline is slipping below annual flood risk levels, exposing residents to escalating threats.

Climate Matters

Rising Seas, Flooding Coasts

As the planet warms and sea levels rise, high tide flooding is putting people at risk more often.

Climate Matters

Picturing Our Future

Climate Central releases an international collection of videos and interactive visualizations of long-term sea level rise that show what we can save—if we choose to act now.

Tool

Coastal Risk Screening Tool

Explore local sea level rise and coastal flooding risks worldwide with maps that use the most advanced available global model of coastal elevations.

Report

Sinking Tax Base

Land and property at risk from rising seas

Climate Matters

Coastal Wetlands at Risk

On World Oceans Day, a new Climate Central study explores how wetlands—and the benefits they provide to coastal communities, economies, and ecosystems—can, or cannot, adapt to rising sea levels.

Climate Matters

Climate change impacts seniors living near the coast

A new Climate Central report examines how climate change threatens America’s aging coastal population—with rising sea levels and increasing hurricane intensity, posing risks to seniors’ safety, health and financial security.