Category One
Wind Speed: 74-95 mph.
Damage: No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery and trees; also some coastal flooding and minor pier damage.
Examples: Irene 1999, Allison 1995.

Category Two
Wind Speed: 96-110 mph.
Damage: Some roofing material, door and window damage to buildings; considerable damage to vegetation, mobile homes and piers. Coastal and low-lying escape routes flood in two to four hours before arrival of the center of the storm. Small craft in unprotected anchorages break moorings.
Examples: Bonnie 1998, Georges 1998 and Gloria 1985.

Category Three
Wind Speed: 111-130 mph.
Damage: Some structural damage to small residences and utility buildings with a minor amount of curtain wall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Terrain continuously lower than five feet above sea level may be flooded inland eight miles or more.
Examples: Keith 2000, Fran 1996, Opal 1995, Alicia 1983 and Betsy 1965.

Category Four
Wind Speed: 131- 155 mph.
Damage: More extensive curtain wall failures with some complete roof structure failure on small residences; major erosion of beaches. Major damage to lower floors of structures near the shore. Terrain continuously lower than ten feet above sea level may be flooded requiring massive evacuation of residential areas as far as six miles.
Examples: Andrew 1992, Hugo 1989 and Donna 1960.

Category Five
Wind Speed: 155 ++++
Damage: Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Major damage to lower floors of all structures located 15 feet above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within five to ten miles of the shoreline may be required.
Examples: Mitch and Gilbert 1988.

Credit: Federal Alliance for Safe Homes, Inc.