How high off the ground are wind speed readings typically taken?

How high off the ground are wind speed readings typically taken?

• A. 10 ft
• B. 40 ft
• C. 6 ft
• D. 20 ft

Answer: (D)

Wind speed readings are taken at about twenty feet above the ground because this height best represents the wind that influences fire spread in the lower atmosphere where fuels interact with flames. Near the surface, wind can be distorted by ground roughness, vegetation, and obstacles, giving readings that don’t reliably reflect how fast a fire will move. If the measurement is too high, it may miss the winds that actually drive the fire’s behavior in the near-ground layer. Twenty feet provides a practical, representative reference for planning prescribed burns, and you’ll often see this height achieved with a portable pole-mounted anemometer in the field.

Wind speed readings are taken at about twenty feet above the ground because this height best represents the wind that influences fire spread in the lower atmosphere where fuels interact with flames. Near the surface, wind can be distorted by ground roughness, vegetation, and obstacles, giving readings that don’t reliably reflect how fast a fire will move. If the measurement is too high, it may miss the winds that actually drive the fire’s behavior in the near-ground layer. Twenty feet provides a practical, representative reference for planning prescribed burns, and you’ll often see this height achieved with a portable pole-mounted anemometer in the field.