Saffir-Simpson Scale Hurricanes are measured on the Saffir-Simpson wind scale. This was introduced to help scale and assess the likely damage from a hurricane. The categories run from 1 - 5. These categories are based on sustained wind speed. The sustained winds are the average winds over a period of one minute. Although wind speed can far exceed the 157mph (Cat 5). Such as Hurricane Irma, which reached 185 mph. No Category 6 exists on the scale as it is agreed that any wind speed in Category 5 reflex near total destruction. So would have no practical benefit.