According to the National Oceanic and Atmospheric Administration, a hurricane is a tropical cyclone — the general term for a circulating weather system — with sustained winds of 74 miles per hour (64 knots) or higher. Hurricanes are called typhoons in the western Pacific and cyclones in the Indian Ocean. The Atlantic hurricane season begins June 1 and ends Nov. 30 each year. An average of 10 tropical storms, of which six become hurricanes, develop over the Atlantic Ocean, Caribbean Sea or Gulf of Mexico each year. About five hurricanes hit the U.S. coastline every three years, and of those, two will be classified as major (category 3, 4 or 5, with winds of 111 mph or greater on the Saffir-Simpson Hurricane Wind Scale).