This is a picture of a thermometer and you can see the mercury in it. it has lines for telling the temperature, and to the right hand side of it are three drops of dew or water.
This Dew Point icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,700 icons, all in the same style and quality.