0 $0.00

Shopping bag

  • No products in the cart.
May 15th, 2020

How to Determine Wind Speed with a Flag

Have you ever been out in the wind and wondered what the wind speed was? Did you know that you can judge wind speed by looking at your flag?  That’s right, there are two methods to determine the wind speed with a flag.

Math Method

When a flag is on a pole perpendicular to the ground, determine what the the angle between the pole and the bottom side of the flag is, then divide by 4. For example, if the angle of your flag with the pole is approximately 40 degrees, the wind speed is roughly 10 mph.

Determine Wind Speed with a Flag

Eyeball Method

Another way to determine the wind speed of a flag is how much it is moving in the wind. When watching a flag flying on an in-ground flagpole, there are few ways it could be waving. Who knew there were multiple ways a flag could fly.

Stage one:

If the flag is not moving, then the wind speed is below 11 mph.

Stage two:

If the flag is moving subtly and sporadically, then the wind speed with between 12-18 mph

Stage three:

If the flag is waving it’s entire length but in a gentle motion then the wind speed it between 19-24 mph

Stage four:

If the flag is waving more violently over its entire length then the wind speed is 25-31 mph

Stage five:

If your flag is fully extended and constantly flapping then the wind speed is 32 mph

When there is a high wind day like stage five, we recommend taking your flag down if possible, to extend the life of your flag. When your flag is left out in a stage five wind, the flag will start to fray much quicker than if you take your flag in for a day or two.

Related posts

Leave a reply