U.S. Wind Zone Map

The wind zone map below shows how the frequency and strength of extreme windstorms vary across the United States.  This map is based on 40 years of tornado history.  Zone IV, the darkest area on the map, has experienced both the greatest number of tornadoes and the strongest tornadoes.  As shown by the map key, wind speeds in Zone IV can be as high as 250 mph.  The tornado hazard in Zone III, while not as great as in Zone IV, is still significant.  In addition Zone III includes coastal areas susceptible to hurricanes.

Source: FEMA