How to judge the wind direction according to the F-shaped sign or small flag?

1- secondary: 1 vertical line 1 horizontal line

Grade 3-4: 1 vertical bar and 2 horizontal bars

Grade 5-6: 1 vertical bar 3 horizontal bar

Grade 7-8: 1 vertical bar 4 horizontal bar.

Above level 8: 1 vertical bar 1 triangle is like a small flag.

Wind speed is the forward speed of the wind. The greater the air pressure difference between two adjacent places, the faster the air flow, the greater the wind speed and the greater the wind force. Therefore, the magnitude of wind is usually expressed by wind power. The unit of wind speed is meters per second or kilometers per hour.

The distance that the wind moves per second-the wind speed, its formula is "from all the way to nine, multiplied by two". It means: from 1 to 9 winds, multiply each level by 2, and you can roughly get the maximum wind speed.

Reference link: China Meteorological Bureau Wind Classification China Meteorological Standard Network