Why do small water droplets occasionally fall in the sky when it’s not raining?

Because there is moisture in the air, when the air rises to a certain height, it will cool and form small water droplets. The small water droplets collide with each other and form large water droplets, which gather together to form clouds in the sky. Clouds float with the movement of air (i.e., wind). When the water in the cloud reaches a certain weight, it will fall and form precipitation. As for sometimes falling and sometimes not falling, it mainly depends on the horizontal flow speed of the air. When the wind speed is high, it will take away a large amount of water vapor in the air, so that it cannot condense into certain water droplets, so it does not necessarily rain even if it is cloudy.