So the other day I was chatting with a colleague about humidity, and how for some reason the weather reports out here never give the humidity, etc. So we looked at the weather report, and my colleague told me that the dew point was the thing to look it, and I had never paid any attention to the dew point before, so I looked it up on Wikipedia.
The dew point is the temperature to which a given parcel of air must be cooled, at constant barometric pressure, for water vapor to condense into water. The condensed water is called dew. The dew point is a saturation point.
The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. Relative humidity of 100% indicates that the dew point is equal to the current temperature (and the air is maximally saturated with water).
And on this Wikipedia page I found a really interesting piece of information:
A dew point of 35 °C (95 °F) was reported in Dhahran, Saudi Arabia at 3 p.m. July 8, 2003. The temperature was 42 °C (108 °F), resulting in an apparent temperature or heat index of 80 °C (176 °F).