A portable noncontact thermometer comprising a hand-held housing defining an aperture for ingress of incident thermal energy from a target location. A thermometer module includes a noncontact thermal energy detector impinged by the incident thermal energy. The thermometer module further includes a microcontroller operative to interpret electrical signals derived from an output of the noncontact thermal energy detector so as to determine temperature at the target location. A graphical display device, such as an LCD dot matrix display device, is fixed with respect to the housing. The display device is capable of providing a graphical user interface having multiple screens variously showing numbers, text and functional icons. Preferably, the screens will display function tabs located adjacent to corresponding buttons on the housing. The tabs will change depending on the varying function that may be implemented by pressing a respective button. The thermometer also includes circuitry, which include the microcontroller, in electrical communication with the graphical display device so as to produce the graphical user interface.