Hurricanes are large, spiraling tropical storms that can pack wind speeds of over 160 miles an hour and unleash more than 2.4 trillion gallons of rain a day.
These tropical storms are known as cyclones in the northern Indian Ocean and Bay of Bengal, and as typhoons in the western Pacific Ocean.
In the Atlantic, hurricane season starts June 1, while in the Pacific it starts May 15. Both end on November 30.
When they come onto land, the heavy rain, strong winds and heavy waves can damage buildings, trees and cars. The heavy waves are called a storm surge.
40 percent of the hurricanes that occur in the United States hit Florida.
Hurricanes rotate in a counter-clockwise direction around the eye. The rotating storm clouds create the "eye wall”, which is the most destructive part of the storm.
The difference between a tropical storm and a hurricane is wind speed – tropical storms usually bring winds of 36-47 miles per hour, whereas hurricane wind speeds are at least 74 miles per hour.
Hurricanes are classified into five categories, based on their wind speeds and potential to cause damage.
Category One -- Winds 74-95 miles per hour
Category Two -- Winds 96-110 miles per hour
Category Three -- Winds 111-130 miles per hour
Category Four -- Winds 131-155 miles per hour
Category Five -- Winds greater than 155 miles per hour
When the National Hurricane Center began giving official names to storms in 1953, they were all female. This practice of using only women’s names ended in 1978.
Sometimes names are "retired" if a hurricane has been really big and destructive. Retired names include Katrina, Andrew and Mitch.
The costliest hurricane to make landfall was Hurricane Katrina, a Category 5 storm that slammed Louisiana in August of 2005. Damages cost an estimated $91 billion.
The deadliest U.S. hurricane on record was a Category 4 storm that hit the island city of Galveston, Texas, on Sept. 8, 1900. Some 8,000 people lost their lives when the island was destroyed by 15-foot waves and 130-mile-an-hour winds.