Dew point is the temperature to which air must be cooled to become saturated with water vapour. When cooled further, the airborne water vapour will condense to form liquid water. When air cools to its dew point through contact with a surface that is colder than the air, water will condense on the surface.

Apparent temperature is the temperature equivalent perceived by humans, caused by the combined effects of air temperature, relative humidity and wind speed. The measure is most commonly applied to the perceived outdoor temperature

Feels like temperature is a measurement of how hot or cold it really feels like outside. The “Feels Like” temperature relies on environmental data including the ambient air temperature, relative humidity, and wind speed to determine how weather conditions feel to bare skin.

Wind-chill or windchill is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values where the formula is valid. When the apparent temperature is higher than the air temperature, the heat index is used instead.
The “wind chill effect” is the perceived decrease in air temperature felt by a body (in the UK at temperatures less than 10 deg C.) due to the wind speed: the greater amount of airflow, the greater cooling effect is produced.

Heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature. This has important considerations for the human body's comfort. When the body gets too hot, it begins to perspire or sweat to cool itself off.

Humidex is an index number used by Canadian meteorologists to describe how hot the weather feels to the average person, by combining the effect of heat and humidity. The term humidex was first coined in 1965. The humidex is a nominally dimensionless quantity based on the dew point.