Wind Chill and Heat Index

Many Weather Stations show values for Wind Chill and Heat Index, but more often that not, these are not different from the current temperature. Why?

This is because Wind Chill only applies when the average wind speed is above 4.8 kph and the temperature is below 10 degrees Celsius.

Heat index only applies when the temperature is above 27 degrees Celsius and the humidity is above 40%.

You will also see Apparent Temperature, which combined both into one measure and Humidex, which is similar to Heat Index.