Saffir-Simpson Hurricane Scale Reference

Hurricane intensity from Category 1 to 5

This reference covers the Saffir-Simpson Hurricane Wind Scale, which rates hurricanes by their maximum sustained wind speed across five categories. It also lists the sub-hurricane tropical-depression and tropical-storm bands. Each entry shows wind speeds in mph and km/h, typical storm surge, and the damage to expect. A classifier converts any sustained wind speed into its category.

How it works

The official scale uses only the maximum 1-minute sustained wind speed. The classifier converts your input to mph first, then finds the band that contains it:

Tropical depression  <= 38 mph
Tropical storm       39 - 73 mph
Category 1           74 - 95 mph
Category 2           96 - 110 mph
Category 3           111 - 129 mph   (major hurricane)
Category 4           130 - 156 mph
Category 5           >= 157 mph

Knots are converted with mph = knots * 1.150779 and km/h with mph = km/h / 1.609344. Storm surge is shown as historical guidance only; the modern scale is wind-only.

What each category means on the ground

Category 1 (74–95 mph): Well-constructed frame homes sustain damage to roof, shingles, gutters, and awnings. Large branches snap; shallow-rooted trees can topple. Power outages are likely and can last several days.

Category 2 (96–110 mph): Roofs are more seriously damaged. Many shallow-rooted trees snap or fall, blocking roads. Near-total power loss expected for days to weeks in affected areas.

Category 3 (111–129 mph — major hurricane): Well-built homes suffer major damage: gable ends collapse, many trees snap or uproot. Electricity and water unavailable for several days to weeks. Evacuation of residents in storm surge risk zones is often ordered.

Category 4 (130–156 mph — major hurricane): Catastrophic damage. Well-built homes can lose most of their roof structure and some exterior walls. Most trees snap or uproot; power poles downed. Residential areas left uninhabitable for weeks to months.

Category 5 (157 mph and above — major hurricane): A high percentage of framed homes are destroyed, with total roof failure and wall collapse. Fallen trees and power poles isolate residential areas. Power outages can last weeks to months. Some areas may be uninhabitable for months or longer.

Why category is an incomplete risk indicator

The Saffir-Simpson scale measures wind intensity only. It does not capture:

• Storm surge, which is the most common cause of hurricane deaths. A large, slow-moving Category 2 can pile far more water ashore than a compact, fast-moving Category 4. Surge depends on storm size, forward speed, approach angle, and the shape of the seabed and coastline.
• Rainfall and inland flooding, which kill more people than wind in many landfalling storms regardless of category. This is especially true for slow-moving storms that stall over land.
• Tornadoes, which are common in the outer bands of landfalling hurricanes.
• Storm size. Wind field diameter varies enormously; a storm’s damaging winds may extend 200 miles from center or only 50.

Emergency managers and forecasters now supplement the Saffir-Simpson category with separate watches and warnings for surge, wind, and rainfall so communities can understand each risk independently.

Tips and notes

• A “major hurricane” is Category 3 or stronger (111 mph and up).
• The jump from Category 4 to 5 is small in wind speed but large in destruction because damage rises roughly with the cube of wind speed — even a 10 mph difference near the top of the scale is significant.
• Inland flooding from rainfall kills more people than wind in many storms, regardless of category.
• A storm that weakens before landfall can still produce catastrophic surge from the large wave field it generated earlier.