6.4. Dew point

Condensation of water vapour in the atmosphere begins when the saturated air mass reaches the dew point. This is level at which the air is not in a position to take up any more moisture. Any further fall in temperature, beyond the dew point, would cause the condensation of the moisture present in the air. In the atmosphere, the nuclei for the condensation of the moisture is provided by the smoke and the dust particles.

Once the condensation of water vapour in the atmosphere has taken place, the moisture present in the atmosphere may take one of the following forms— dew, frost, fog, mist, clouds, etc. This will be according to the conditions prevalent in the atmosphere.