The dry-bulb temperature was originally measured with a mercury thermometer having a dry bulb. It is commonly the measure of atmospheric temperature without the presence of moisture.
The dry bulb temperature is higher than the wet-bulb temperature, and the wet-bulb temperature is higher than the dew point.
Source: Hardy, Colin C., Ottmar, Roger D., Peterson, Janice L., Core, John E., and Seamon, Paula. 2001. Smoke Management Guide for Prescribed and Wildland Fire 2001 Edition. Produced by the National Wildfire coordinating Group Fire Use Working Team.