Dew is not considered a form of precipitation because it is formed through a different process than traditional forms of precipitation like rain, snow, or hail. While precipitation occurs when moisture in the atmosphere condenses into larger droplets and falls to the ground due to gravity, dew forms directly from the condensation of water vapor in the air on cooler surfaces, typically overnight.
When the temperature drops in the evening, the air can no longer hold all of its moisture, and this excess moisture condenses into tiny water droplets that accumulate on surfaces like grass, leaves, and cars. This process is known as dew formation, and it is not tied to weather systems or atmospheric disturbances that usually cause precipitation.
In summary, while dew involves condensation, it occurs at ground level and is not associated with the atmospheric processes that generate precipitation, making it distinct in its formation and classification.