Every hurricane gets a number, but what does it mean? Hurricane winds aren't the only extreme danger.

A graphic within the Post's story shows how wind defines each hurricane category.
(Digital art, The Washington Post)

Every hurricane gets a category number designed to guide response efforts, and while most people are used to hurricane weather jargon including the category number, what the number represents is somewhat mysterious. The five categories are based on the Saffir-Simpson Hurricane Wind Scale, report Amudalat Ajasa, Aaron Steckelberg and Julie Vitkovskaya of The Washington Post. "The scale only measures one component of a hurricane: the wind. Each category is divided by a range of wind speeds, estimating potential damage and impacts on properties . . .The numbers categorize hurricanes based on maximum sustained wind speeds ranging from 74 mph to 157 mph and above." Each category is describer here:

Category 1: Wind speeds range from 74-95 mph. Dangerous winds will produce some damage. Metal roof coverings, shingles and gutters will sustain damage. Shallow-rooted trees can be uprooted, and power lines can fall.

Category 2: Wind speeds range from 96-110 mph. Extremely dangerous winds will cause extensive damage. Major roof and siding, commercial signage, fences and canopies will be damaged or destroyed. Shallow-rooted trees will probably be snapped or uprooted, along with close to total power loss.

Category 3: Wind speeds range from 111-129 mph. Devastating damage will occur. Homes may experience roof failure and wall collapse. Windows will be blown out of high-rise buildings. Commercial signage, fences and canopies will face destruction. Trees will be snapped or uprooted. Power and water will be lost.

Category 4: Wind speeds range from 130-156 mph. Catastrophic damage will occur, including the destruction of most homes with the collapse of all walls and roof structure. Commercial signage, fences and canopies will be destroyed. Trees and power poles will be downed or snapped. Most of the area will be uninhabitable for weeks or months.

Category 5: Wind speeds range from 157 mph or higher. Almost complete destruction of all homes. Many industrial buildings and low-rise buildings will be destroyed. Nearly all the windows from high-rise buildings will be blown out. Near-total destruction of all commercial signage, fences and canopies. Nearly all trees and power poles will be downed or snapped. Most of the area will be uninhabitable for weeks or months.

The scale isn't a perfect measurement, and emergency responders, government officials and the public need to remember that wind isn't the only consideration with hurricanes. Storm surges can be equally deadly. The Post reports, "As a hurricane barrels across the open ocean, strong winds drive the water forward. Once the water reaches the shore, it combines with normal tides and creates the storm surge.

Storm surge is the leading cause of hurricane-related deaths in the United States, according to the National Weather Service."

In 2008, Hurricane Ike was designated a Category 2 hurricane. "But the wind wasn’t what caused the most damage," the Post reports. "The storm had a surge of more than 20 feet, the largest storm surge on record for a Category 2 hurricane. Imagine rushing water the height of two basketball hoops stacked on top of each other barreling toward homes, cars and buildings. . . . The storm claimed 195 lives and resulted in $30 billion in damage. It wasn’t even considered a major hurricane."