A high dew point humidity sensor includes an enclosure assembly, an ambient temperature sensor, air sample intake and exhaust openings, a fluid-moving device, a heater block assembly, an internal temperature sensor, a humidity sensor chip, and a controller. The controller is configured to: (i) collect a measured ambient temperature from the ambient temperature sensor; (ii) collect a measured humidity of sample air from the humidity sensor chip; (iii) collect a measured temperature from the internal temperature sensor; and (iv) control operation of the heater block assembly based, at least in part, on the measured ambient temperature and the measured temperature from the internal temperature sensor.