The National Hurricane Center uses the Saffir-Simpson Hurricane Wind Scale to determine storm categories. It’s a 1 to 5 rating based only on a hurricane’s maximum sustained wind speed and doesn’t consider other potential deadly hazards like storm surge, rainfall, flooding and tornadoes.
Here are the wind thresholds for the various hurricane categories and the kind of damage they can cause, per the National Hurricane Center:
Breaking Down Hurricane Categories
Category 1 (max sustained winds of 74-95 mph): Very dangerous winds will produce some damage. Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
Category 2 (max sustained winds of 96-110 mph): Extremely dangerous winds will cause extensive damage. Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
Category 3 (max sustained winds of 111-129 mph): Devastating damage will occur. Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
Category 4 (max sustained winds of 130-156 mph): Catastrophic damage will occur. Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or 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 will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
Category 5 (max sustained winds of 157 mph or higher): Catastrophic damage will occur. A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. 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. Source: NBC Boston