Weather is the condition of the atmosphere at a particular time, in terms of temperature, wind, moisture and atmospheric pressure. The sun causes all these weather changes. The sun affects the movement of air. It also changes the form of water making the day cloudy, rainy or sunny.

The amount of water vapour in the air is called humidity. The sun heats the water present on Earth. The water vapour thus formed is absorbed by the air. Warm air can hold more water vapour in it.

In nature, condensation can be seen in the form of dew, frost, fog, hail and snow. When it is very cold, dew drops freeze into tiny ice crystals called frost.

The level of underground water at a place is called the "water table." Most of the rain falls on the ground and seeps through the layers of soil to form underground water. This can be drawn out with the help of wells and tube wells.