3.4.3 Precipitation

What happens when the air simply can’t hold any more water vapour?

• Precipitation is water falling from the atmosphere as rain, drizzle, snow, sleet or hail .
• Precipitation occurs when air becomes saturated with water vapour.
• It condenses and falls due to gravity.
• Main factors affecting it are winds, mountains and seasons .
• Rain is the most common form and lowers temperature.
• A long absence of rain results in a dry climate .
• Most groundwater comes from rainwater .