Hurricanes Facts & Terms
The Atlantic hurricane season begins June 1—the peak is from mid-August to late October—and ends November 30.
Hurricane Facts
The most significant danger comes from a hurricane’s storm surge, when the surface of the ocean rises due to the force of a hurricane’s winds.
Debris, such as signs, roofing material, siding, and small items left outside, becomes flying missiles in a hurricane. And winds can hold at hurricane strength well inland.
Hurricanes and tropical storms also produce tornadoes. These tornadoes most often occur in thunderstorms embedded in rain bands well away from the center of the hurricane; however, they can also occur near the eyewall.
Hurricanes and tropical storms can produce widespread torrential rains, often in excess of 6 inches; this can produce deadly and destructive floods.
Saffir-Simpson Hurricane Scale
Hurricanes are measured using the Saffir-Simpson scale, a 1-to-5 rating based on the storm’s sustained wind speed. This scale estimates potential property damage.
- Category 1 (74 to 95 mph winds): Damage primarily to shrubbery, trees, foliage, and unanchored mobile homes. No real damage to other structures. Storm surge is typically 4 to 5 feet above normal.
- Category 2 (96 to 110 mph winds): Some trees blown down. Major damage to exposed mobile homes. Some damage to roofing materials, windows, and doors. Storm surge is typically 6 to 8 feet above normal.
- Category 3 (111 to 130 mph winds): Large trees blown down. Mobile homes destroyed. Some structural damage to the roofing materials of buildings. Some structural damage to small buildings. Storm surge is typically 9 to 12 feet above normal.
- Category 4 (131 to 155 mph winds): Trees blown down. Destruction of mobile homes. Extensive damage to roofing materials, windows, and doors. Complete failure of roofs on many small residences. Storm surge is typically 13 to 18 feet above normal.
- Category 5 (winds over 155 mph): Complete failure of roofs on many residences and industrial buildings. Extensive damage to windows and doors. Some complete building failures. Storm surge is typically greater than 18 feet above normal.
Terms to Understand
- Hurricane Watch: Hurricane conditions are possible in a specified area, usually within 36 hours.
- Hurricane Warning: Hurricane conditions are expected in a specified area, usually within 24 hours.
- Tropical Storm Watches and Warnings: Take these alerts seriously. Although tropical storms have lower wind speeds than hurricanes, they often bring life-threatening flooding and dangerous winds. Take precautions immediately.