58–70 m/s, 113–136 knots 130–156 mph, 209–251 km/h
50–58 m/s, 96–112 knots 111–129 mph, 178–208 km/h
43–49 m/s, 83–95 knots 96–110 mph, 154–177 km/h
33–42 m/s, 64–82 knots 74–95 mph, 119–153 km/h
18–32 m/s, 34–63 knots 39–73 mph, 63–118 km/h
≤17 m/s, ≤33 knots ≤38 mph, ≤62 km/h
The Saffir-Simpson hurricane wind scale is a scale to measure the intensity of tropical cyclones, primarily tropical cyclones in the Atlantic and East Pacific basins, where they are known as hurricanes. The scale was invented by Herbert Saffir and Robert Simpson in 1971, and was first officially used in 1973. Officially, the scale is used for hurricanes in excess of 74 mph, and has a five-category system for measuring the intensity of a tropical cyclone. The lowest classification is Category 1 (74-95 mph), followed by Category 2 (96-110 mph), then Category 3 (111-129 mph), then Category 4 (130-156 mph), and finally Category 5 (157+ mph). The Saffir-Simpson scale only takes into account the maximum winds in a storm, and does not consider barometric pressure, storm surge, or storm size; as a result, the scale is sometimes criticized. For instance, barometric pressures can vary largely in a storm of the same intensity on the SSHWS. For example, while both storms had maximum sustained winds of 110 mph and were category 2 hurricanes on the Saffir-Simpson Hurricane Wind Scale, Hurricane Alex in 2010 had a minimum pressure of 946 millibars, and Hurricane Florence of 1994 had a significantly higher minimum pressure of 972 millibars.