1. Cooling of the air: Warm air can hold more moisture than cold air. When air cools, it reaches its "dew point" – the temperature at which it can no longer hold all of its water vapor. The excess water vapor then condenses into liquid water droplets. This is why you see dew forming on grass in the morning.

2. Presence of condensation nuclei: Water vapor needs a surface to condense onto. These surfaces can be tiny particles in the air like dust, smoke, or salt. These are called condensation nuclei. Without them, condensation would occur much more slowly, if at all.

3. Saturation: For condensation to occur, the air must be saturated with water vapor. This means that the air is holding as much moisture as it can at its current temperature. This saturation can occur through a few different mechanisms, including:

* Cooling: As mentioned above, cooling air can lead to saturation.

* Evaporation: When water evaporates from a surface, it adds moisture to the air. If enough water evaporates, the air can become saturated.

* Mixing: When two air masses with different moisture content mix, the resulting air mass may be saturated.

These three conditions work together to create the environment necessary for condensation.