Which two factors dictate windchill?

Wind chill is a measure that combines air temperature and wind speed to determine how cold it feels to exposed skin. The rationale behind this is that wind can remove heat from the body more quickly than still air, making it feel significantly colder than the actual air temperature.

The two primary factors that affect wind chill are wind speed and air temperature. When the wind blows, it disperses the layer of warm air that typically surrounds the body, thereby increasing heat loss. Higher wind speeds result in a greater cooling effect, making it feel much colder than the actual air temperature indicates. Therefore, combining these factors—where lower temperatures and higher winds amplify the chilling effect—correctly identifies why wind speed and air temperature are crucial in assessing wind chill.

Humidity, while it can affect overall weather perception and comfort, does not directly factor into wind chill calculations in the same way that wind speed and air temperature do.