Hurricane Irma From Space

Increased Hurricane Intensity

Did you know?

  • From 1980-2014, tropical cyclones that made landfall in the United States cost more in damages than any other type of natural disaster.
  • In a warmer climate, hurricane precipitation is projected to increase by about 20% near the eye of the storm and the average storm intensity is expected to increase 2-11%.

There are many environmental factors that contribute to development of a tropical cyclone. These include, but are not limited to, ocean water temperatures, atmospheric temperatures, air moisture levels, distance from the equator, and wind speeds and directions. Whether or not a tropical cyclone is categorized as a tropical storm or hurricane depends on its maximum sustained wind speed.

The intensity of North Atlantic hurricanes and the number of Category 4 and 5 hurricanes have increased since the 1980s.These increases are due in part to warmer sea surface temperatures in the areas where Atlantic hurricanes form and pass through. An active area of research involves determining how much of this sea surface temperature increase can be attributed to natural causes versus human causes and whether the frequency and duration of  hurricanes will continue to increase in the future.

While there is uncertainty as to whether the frequency and duration of hurricanes will increase, scientists project that storm intensity and rainfall rates will increase in the future. Hurricane-related impacts can be magnified by other environmental factors such as increasing sea levels. Additionally, a growing concentration of people and properties in coastal areas where hurricanes strike can result in increased damages when these storms make landfall. For example, sea levels rose a foot over the last century off the coast of New York City. As a result, the storm surgeflooding, and associated damages to infrastructure and communities were more severe when Hurricane Sandy hit than they would have been a few decades ago.

Learn More


  • Melillo, Jerry M., Terese (T.C.) Richmond, and Gary W. Yohe, Eds. 2014. Climate Change Impacts in the United States: The Third National Climate Assessment. Washington: U.S. Global Change Research Program.
  • NASA. 2005. "Hurricane Katrina GOES Clouds." Accessed September 18.
  • NOAA. 2012. "Superstorm Sandy and Sea Level Rise." Accessed September 18.
  • NOAA. 2014. "How do tropical cyclones form?" Accessed Septmeber 18, 2015.
  • NOAA. 2015. "Billion-Dollar Weather and Climate Disasters: Summary Stats." Accessed September 18.
  • NOAA. 2015. "Global Warming and Hurricanes." Accessed September 18.
  • NOAA. 2015. "Tropical Cyclone Climatology." Accessed September 18.
  • Pielke Jr., Roger A, Joel Gratz,  Christopher W. Landsea, Douglas Collins, Mark A. Saunders, and Rade Musulin. 2008. "Normalized Hurricane Damage in the United Staets: 1900-2005." Natural Hazards Review 9: 28-42.
  • US EPA. 2015. "Climate Impacts on Water Resources." Accessed September 18.