Dew Proper
(Section 3.2.1.4.2)Definition: Dew proper: Deposit of water drops on objects whose surface is sufficiently cooled, generally by nocturnal radiation, to cause direct condensation from the surrounding air.
Dew proper is ordinarily deposited on objects at or near the ground, mainly on their horizontal surfaces. Dew is observed especially when the air is calm and the sky is clear.
Dew should not be confused with the deposit of drops from fog on exposed surfaces, or with droplets of water exuded by plants (a phenomenon known as guttation), which often takes place at the same time as deposits of dew but which can also occur separately.