The Saffir-Simpson Hurricane Wind Scale classifies hurricanes into five categories based on maximum sustained wind speed, providing a simple way to communicate the potential for wind damage. Developed in 1971 by civil engineer Herbert Saffir and meteorologist Robert Simpson (then director of the US National Hurricane Center), the scale has been in operational use since 1973.
The categories are: Cat 1 (119–153 km/h — some damage to roofs, gutters, and trees), Cat 2 (154–177 km/h — major roof damage, shallow-rooted trees uprooted), Cat 3 (178–208 km/h — devastating damage, structural damage to small buildings), Cat 4 (209–251 km/h — catastrophic damage, most trees snapped, prolonged power outages), and Cat 5 (≥252 km/h — catastrophic destruction, many structures destroyed). Categories 3–5 are classified as major hurricanes.
The scale has important limitations: it only addresses wind and does not account for storm surge (which is the greatest killer in hurricanes), rainfall-induced flooding, or tornado threats. Hurricane Katrina (2005) made landfall as Category 3 by wind but produced a Category 5-level storm surge of 8.5 m. Similarly, Hurricane Harvey (2017) was "only" Category 4 by wind but dropped 1,539 mm of rain on Texas. For this reason, the scale was renamed from "Hurricane Scale" to "Hurricane Wind Scale" in 2012 to clarify its scope. In the eastern Atlantic basin, which occasionally affects the Azores, Canary Islands, and even the Iberian Peninsula, the scale is used for subtropical and tropical systems.