Hurricanes are categorized according to wind speeds based on the Saffir-Simpson Hurricane Scale. The weakest hurricanes are Category 1, defined by wind speeds starting at 74 miles per hour and storm surges of 4 to 6 feet. The scale ranges to a Category 5 where wind speeds are in excess of 155 miles per hour, and storm surges can reach 18 feet or more. Saffir-Simpson Hurricane Scale Category Sustained Winds Damage 1 75-95 mph Very dangerous winds will produce some damage.Â Roofs, siding, shingles, and gutters damaged. Large tree branches will snap. Damage to power lines will result in power outages. 2 96-110 mpg Extremely dangerous winds will cause extensive damage. Major roof and siding damage. Shallowly rooted trees will snap or uproot and block roads. Near-total power loss is expected with outages that could last weeks. 3 111-129 mph Devastating damage will occur. Well-built framed homes may see major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking roads. Electricity and water will be unavailable for up to weeks after the storm. 4 (major) 130-156 mph Catastrophic damage will occur. Well-built framed homes may have loss of most of the roof and some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages could months. Most of the area will be uninhabitable for weeks or months. 5 (major) 157 mph or higher Catastrophic damage will occur. A large number of framed homes will be destroyed. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.