How does humidity affect our weather?

Basically, the more water vapor in our atmosphere, the more possibility of precipitation.

Precipitation happens when the air rises and causes condensation of water vapor into liquid water droplets. This is the beginning of the formation of precipitation! These little droplets grow through a process called “collision-coalescence”. During collision-coalescence, these droplets come together and form larger drops. Once the drops are a certain size, they become too heavy for the air and the drops fall as precipitation from the clouds.