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Explained: How Hurricane Categories Work in One Chart

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See this visualization first on the Voronoi app.

This graphic explains the Saffir-Simpson Hurricane Wind Scale, which is widely used to categorize the intensity and damage potential of impending hurricanes.

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Explainer: How Hurricane Categories Work

This was originally posted on our Voronoi app. Download the app for free on iOS or Android and discover incredible data-driven charts from a variety of trusted sources.

Hurricane Milton made landfall in Florida as a Category 3 hurricane, and exited the area as a Category 1 storm. What do these hurricane categories mean?

We visualize the Saffir-Simpson Hurricane Wind Scale, which measures maximum sustained wind speed for one minute to estimate likely property damage.

Data is sourced from the Hurricane Center at National Oceanic and Atmospheric Administration.

Importantly it does not take into account other related weather conditions from a hurricane: storm surges (tsunami-like phenomenon of rising water), flooding, and tornadoes.

Hurricane Categories Measure Wind Speeds

At the very lowest rung, even a Category 1 storm (74-95 mph winds) can cause significant damage—broken roofs, bent gutters, snapped branches, and toppled trees, especially those with shallow roots.

As the wind speed gets higher, the damage potential worsens, as seen in the table below.

CategoryMaximum Sustained
Winds (1 Minute)
KMPH EquivalentDescription
174-95 mph119-153 km/hMinor damage to
homes and short
term power loss
296-110 mph154-177 km/hMajor roof damage to
buildings and near-total
power loss
3111-129 mph178-208 km/hElectricity and water
unavailable for up to
several weeks
4130-156 mph209-251 km/hSevere damage to
homes, with long
lasting power outages
and road blockages
5157 mph or higher252 km/h or higherHigh % of homes
destroyed; area
uninhabitable for
weeks or months

However, hurricanes often weaken as they approach land due to friction with the surface and reduced access to the warm ocean waters that fuel them.

For example, Hurricane Katrina strengthened into a Category 5 over the waters of the Gulf of Mexico, but reduced to a Category 3 upon landfall. And as stated above, Milton lost wind speed after it moved through the Floridian west coast.

And all of this is still measuring only wind damage. Often the majority of destruction occurs after storm surges and flooding.

In fact there has been discussion regarding a separate storm surge scale to help forecasting. However, local underwater topography has an outsized role in determining the impact of a storm surge, rendering any one scale inefficient.

Learn More on the Voronoi App

Despite being a category 3, Hurricane Katrina ranks first by the damage costs, leapfrogging other more severe storms. Check out The Costliest Hurricanes to Hit the U.S. for more information.

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