Measuring hurricane intensity: the Saffir-Simpson scale

The Saffir-Simpson scale shown in the table below is the most frequently used sytem for measuring hurricane intensity. It ranks hurricanes on a scale from 1 (74mph) to 5 (155mph or higher) based on the intensity of their maximum sustained winds.

Category	Max. sustained wind speed		Min. surface pressure	Storm surge
	mph	m/s	mb	ft	m
1	74 – 95	33 – 42	< 980	3 – 5	1.0 – 1.7
2	96 – 110	43 – 49	979 – 965	6 – 8	1.8 – 2.6
3	111 – 130	50 – 58	964 – 945	9 – 12	2.7 – 3.8
4	131 – 155	59 – 69	944 – 920	13 – 18	3.9 – 5.6
5	156+	70+	> 920	19+	5.7+

The following list describes the damage caused by each category on the Saffir-Simpson scale, indicating examples from the recent past. Note that tropical storms are not on this scale, but can produce extensive damage through ensuing floods. Hurricane categories 3-5 are collectively referred to as major (or intense) hurricanes; they cause over 83% of the damage in the US even though they account for only 21% of tropical cyclone landfalls (Landsea 1993).

1 - Minimal damage

Damage primarily to shrubbery, trees, foliage, and unanchored homes. No real damage to other structures. Some damage to poorly constructed signs. Low-lying coastal roads inundated, minor pier damage, some small craft in exposed anchorage torn from moorings.
Example: Hurricane Earl (1998)

2 - Moderate damage

Considerable damage to shrubbery and tree foliage; some trees blown down. Major damage to exposed mobile homes. Extensive damage to poorly constructed signs. Some damage to roofing materials of buildings; some window and door damage. No major damage to buildings. Coast roads and low-lying escape routes inland cut by rising water 2 to 4 hours before arrival of hurricane centre. Considerable damage to piers. Marinas flooded. Small craft in unprotected anchorages torn from moorings. Evacuation of some shoreline residences and low-lying areas required.
Example: Hurricane Georges (1998)

3 - Extensive damage

Foliage torn from trees; large trees blown down. Practically all poorly constructed signs blown down. Some damage to roofing materials of buildings; some wind and door damage. Some structural damage to small buildings. Mobile homes destroyed. Serious flooding at coast and many smaller structures near coast destroyed; larger structures near coast damaged by battering waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane centre arrives. Flat terrain 5 feet of less above sea level flooded inland 8 miles or more. Evacuation of low- lying residences within several blocks of shoreline possibly required.
Example: Hurricane Fran (1996)

4 - Extreme damage

Shrubs and trees blown down; all signs down. Extensive damage to roofing materials, windows and doors. Complete failures of roofs on many small residences. Complete destruction of mobile homes. Flat terrain 10 feet of less above sea level flooded inland as far as 6 miles. Major damage to lower floors of structures near shore due to flooding and battering by waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane centre arrives. Major erosion of beaches. Massive evacuation of all residences within 500 yards of shore possibly required, and of single- story residences within 2 miles of shore.
Example: Hurricane Lili (2002)

5 - Catastrophic damage

Shrubs and trees blown down; considerable damage to roofs of buildings; all signs down. Very severe and extensive damage to windows and doors. Complete failure of roofs on many residences and industrial buildings. Extensive shattering of glass in windows and doors. Some complete building failures. Small buildings overturned or blown away. Complete destruction of mobile homes. Major damage to lower floors of all structures less than 15 feet above sea level within 500 yards of shore. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane centre arrives. Massive evacuation of residential areas on low ground within 5 to 10 miles of shore possibly required.
Example: Hurricane Camille (1969), Hurricane Andrew (1992)