Saffir-Simpson Hurricane Scale

The Saffir-Simpson Hurricane Scale is a scale classifying hurricanes by the intensity of their sustained winds, developed in 1969 by civil engineer Herbert Saffir and National Hurricane Center director Bob Simpson. Classifications are used to gauge the likely damage and flooding a hurricane will cause upon landfall.

The initial scale was developed by Saffir while on commission from the United Nations to study low-cost housing in hurricane-prone areas. While performing the study, Saffir realized there was no simple scale for describing the likely effects of a hurricane. Knowing the utility of the Richter magnitude scale in describing earthquakes, he devised a 1-5 scale based on wind speed that showed expected damage to structures. Saffir gave the scale to the NHC, and Simpson added in the effects of storm surge and flooding.

The five categories are, in order of increasing intensity:

Category 1	Sustained winds	74-95 mi/h	64-82 kt	119-153 km/h
	Storm surge;	4-5 ft		1.2-1.5 m
	Central pressure;	28.94 in.		980 mb
	Potential damage	No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal flooding and minor pier damage.
Category 2	Sustained winds	96-110 mi/h	83-95 kt.	154-177 km/h
	Storm surge	6-8 ft.		1.8-2.4 m
	Central Pressure	28.50-28.91 in.		965-979 mb
	Potential damage	Some roofing material, door, and window damage. Considerable damage to vegetation, mobile homes, etc. Flooding damages piers and small craft in unprotected moorings may break their moorings.
Category 3	Sustained winds	111-130 mi/h	96-113 kt.	178-209 km/h
	Storm surge	9-12 ft.		2.7-3.7 m
	Central pressure	27.91-28.47 in.		945-964 mb
	Potential damage	Some structural damage to small residences and utility buildings, with a minor amount of curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Terrain may be flooded well inland.
Category 4	Sustained winds	131-155 mi/h	114-135 kt.	210-249 km/h
	Storm surge	13-18 ft.		4.0-5.5 m
	Central pressure	27.17-27.88 in.		920-944 mb
	Potential damage	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	Sustained winds	≥156 mi/h	≥136 kt.	≥250 km/h
	Storm surge	≥18 ft.		≥5.5 m
	Central pressure	<27.17 in.		<920 mb
	Potential damage	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.

All wind speeds are based on a one-minute average. Central pressure values are approximate.

See also

• The Beaufort scale

External Links

• Descriptions of the likely damage and flooding caused by each category of hurricane
• Interview with Herbert Saffir, contains description of the scale's history