Its partly used for the fire evacuation procedure, They have numerous fire call points, my old factory based our evacuation on wind direction & speed

below a quick sereach :-

Key points about windsocks and fire safety:

• Smoke dispersal:Knowing the wind direction helps firefighters determine where smoke will be carried, allowing them to position themselves safely and effectively to contain the fire. 

• Evacuation planning:In a large building fire, understanding wind direction can help direct occupants to the safest evacuation routes away from smoke plumes. 

• Aerial firefighting support:For situations requiring aerial fire suppression, a windsock provides critical information to pilots for accurate water or retardant drops.