A data capture device includes a housing supporting a window at a scan opening, a data capture module with a scanner field of view directed through the scan window, a heater controllable to heat the window, a non-contact temperature sensor with a sensor field of view directed at the scan window, an auxiliary temperature sensor, a humidity sensor, and a controller. The controller is configured to receive (i) a window temperature from the non-contact temperature sensor, (ii) an external ambient temperature from the auxiliary temperature sensor, and (iii) an external ambient humidity from the humidity sensor. The controller then determines a dew point according to the ambient temperature and the ambient humidity, and selects a power level for the heater based on a comparison of the window temperature and the dew point.