According to NASA estimates, around 85 storms achieve hurricane status each year. A storm is classified as a hurricane when its winds reach or exceed 74 miles per hour. Storms can maintain hurricane-force winds ranging anywhere from a few hours to a few weeks.
Most hurricanes occur in the Pacific Ocean, although the hurricanes most likely to make landfall in the United States emerge in the Atlantic Ocean. Hurricanes in the South Pacific and Indian Ocean may also be called cyclones or typhoons. Predicting the amount of hurricanes likely to occur each year is based on such factors as El Nino and African rainfall.