This scale was developed in the early 1970s by Herbert Saffir, a consulting engineer in Coral Gables, Florida, and Dr. Robert Simpson, then Director of the National Hurrican Center. The scale is based primarily on wind speeds and includes estimates of barometric pressure and storm surge associated with each of the five categories.
1 – Minimal PRESSURE: Greater than 980 mb or 28.94 in. WINDS: 74 to 95 mph. SURGE: 4 to 5 feet.
2 – Moderate PRESSURE: 965 to 979 mb or 28.5 to 28.91 in. WINDS: 96 to 110 mph. SURGE: 6 to 8 feet.
3 – Extensive PRESSURE: 945 to 964 mb or 27.91 to 28.47 in. WINDS: 111 to 130 mph. SURGE: 9 to 12 feet.
4 – Extreme PRESSURE: 920 to 944 mb or 27.17 to 27.88 in. WINDS: 131 to 155 mph. SURGE: 13 to 18 feet.
5 – Catastrophic PRESSURE: less than 920 mb or 27.17 in. WINDS: Greater than 155 mph. SURGE: Greater than 18 feet.
CATEGORY 1 (Minimal) damage primarily restricted to shrubbery, trees and unanchored mobile homes; no substantial damage to other structures; some damage to poorly constructed signs, low lying roads inundated; minor damage to piers; small craft in exposed anchorages torn from moorings.
CATEGORY 2 (Moderate) considerable damage to shrubbery and tree foliage, some trees blown down; major damage to exposed mobile homes; extensive damage to poorly constructed signs and some damage to window, doors and roofing materials of buildings, but no major destruction to buildings. Coastal roads and low lying escape routes inland cut off by rising water about 2 to 4 hours before landfall; considerable damage to piers and marinas flooded; small craft in protected anchorage torn from moorings. Evacuation of some shoreline residences and low lying areas required.
CATEGORY 3 (Extensive) foliage torn from trees; large trees blown down; poorly constructed signs blown down; some damage to roofing, windows and doors; some structural damage to small buildings; mobile homes destroyed. Serious flooding along the coast; many small structures near the coast destroyed; larger coastal structures damaged by battering waves and floating debris. Low lying escape routes inland cut off by rising water about 3 to 5 hours before landfall; flat terrain 5 feet or less above sea level flooded up to 8 or more miles inland. Evacuation of low lying residences within several blocks of shoreline may be required.
CATEGORY 4 (Extreme) shrubs, trees and all signs blown down; extensive damage to roofs, windows and doors, with complete failure of roofs on many smaller residences; mobile homes demolished. Flat terrain 10 feet or less above sea level flooded inland as far as 6 miles; flooding and battering by waves and floating debris cause major damage to lower floors of structures near the shore; low lying escape routes inland out off by rising water about 3 to 5 hours before landfall; major erosion of beaches massive evacuation of all residences within 500 yards of the shore may be required, as well as of single story residences in low ground within 2 miles of the shore.
CATEGORY 5 (Catastrophic) trees, shrubs and all signs blown down; considerable damage to roofs of buildings, with very severe and extensive damage to windows and doors; complete failure on many roofs of residences and industrial buildings; extensive shattering of glass in windows and doors; complete buildings destroyed; small buildings overturned or blown away; mobile homes demolished. Major damage to lower floors of all structures less than 15 feet above sea level within 1500 feet of the shores. Low lying escape routes inland out off by rising water about 3 to 5 hours before landfall; major erosion of beaches. Massive evacuation of residential areas on low ground within 5 to 10 miles of the shore may be required.