weather term
Dew Point
The temperature at which air becomes saturated with moisture and water vapour starts to condense into dew, fog or clouds.
Unlike relative humidity, dew point is an absolute measure of how much moisture is actually in the air, which makes it a more reliable way to judge how muggy a day will feel. A dew point below about 10°C feels comfortably dry, while anything above 20°C usually feels noticeably sticky regardless of the air temperature itself. When the air temperature drops to match the dew point overnight, moisture condenses out as dew, or as fog if it happens near the ground.
Read the full article: What Does "Feels Like" Temperature Actually Mean?.