Two different time scales
Average wind speed is calculated over a defined time interval. A gust is a brief peak above that level. Gusts are therefore usually higher and describe the sudden load experienced by a vehicle, tree, awning, small boat or hiker.
Services may use different averaging or gust durations. When comparing sources, check the method instead of looking only at the number.
Terrain amplifies gusts
Passes, ridges, valley exits and gaps between buildings accelerate airflow. Turbulence on the lee side of a mountain can produce large fluctuations even when the regional average appears moderate.
Coastal shape changes wind close to shore. On a road, a crosswind gust over a bridge or exposed section may matter more than the average value forecast for the nearest town.
Which value should I use?
Use average wind for the sustained sea state and prolonged loading. Always inspect maximum gusts for small-craft safety, driving, work at height and mountain activity.
The Beaufort scale primarily corresponds to observed or sustained wind. A brief gust should not be converted and compared as though it were a long-lasting mean wind.
This guide is educational. For safety-critical decisions, use current observations and follow the competent official authorities.