A calibrated airflow sensor and monitoring method are provided. The monitoring method which includes: providing an airflow sensor positioned within an electronic system to be at least partially air-cooled, the airflow sensor including at least one temperature sensor and a heater associated with one temperature sensor of the at least one temperature sensor; calibrating, with the airflow sensor positioned within the electronic system, a duty cycle for use in powering the heater associated with the one temperature sensor; and providing a controller configured to use the calibrated duty cycle in powering the heater of the temperature sensor during airflow monitoring of the electronic system, and to obtain a hot temperature (Thot) reading from the one temperature sensor having the associated heater, and to determine, based at least in part on the hot temperature (Thot) reading, whether to issue an airflow warning.