Wind speed is the rate at which air moves past a fixed point. It is measured in units such as meters per second, kilometers per hour, or miles per hour. Sustained speed is usually averaged over a short period; gusts are the peak speeds within that period.

Anemometers of various designs provide the measurements. At higher altitudes, radar, aircraft, and satellite techniques estimate wind speed. The Beaufort scale offers a descriptive alternative based on observed effects when instruments are unavailable.

Wind speed determines the force exerted on structures, the power available to turbines, and the severity of storms. Design codes for buildings and bridges incorporate expected extreme wind speeds. In forecasts, both sustained winds and gusts are reported because the latter often cause the most damage.

• Rate of air movement
• Measured by anemometers
• Includes sustained and gust values
• Critical for safety and energy