Glossary of Common Hurricane Terms

From the National Hurricane Center:

Tropical Storm -  Winds 39-73 mph

Category 1 Hurricane — winds 74-95 mph 64-82 kt
No real damage to buildings. Damage to unanchored mobile homes. Some damage to poorly constructed signs. Also, some coastal flooding and minor pier damage.

Category 2 Hurricane — winds 96-110 mph 83-95 kt
Some damage to building roofs, doors and windows. Considerable damage to mobile homes. Flooding damages piers and small craft in unprotected moorings may break their moorings. Some trees blown down. 

Category 3 Hurricane — winds 111-130 mph 96-113 kt
Some structural damage to small residences and utility buildings. Large trees blown down. Mobile homes and poorly built signs destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Terrain may be flooded well inland. 

Category 4 Hurricane — winds 131-155 mph 114-135 kt
More extensive curtainwall failures with some complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well inland. 

Category 5 Hurricane — winds 156 mph and up 135+ kt
Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Flooding causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas may be required.