temperature difference relative humidity
Many times, relative humidity can be misleading. For example, a temperature of 30 and a dew point of 30 will give you a relative humidity of 100%, but a temperature of 80 and a dew point of 60 produces a relative humidity of 50%. It would feel much more humid on the 80 degree day with 50% relative humidity than on the 30 degree day with a 100% relative humidity.