A system and method for controlling a fan is disclosed. A single control signal value for controlling the fan, such as a single PWM duty cycle value for a corresponding PWM generator output powering the fan, may be calculated by combining sensor data from two or more temperature zones. In one embodiment, the single PWM duty cycle value may be determined based on the temperature in a first zone, for example the CPU, with an additional factor based on the temperature in a second zone, for example the ambient temperature of a PC enclosure. In one embodiment, the final single PWM value is determined by adding an offset value to a PWM value calculated based on the current temperature of the first zone, where the offset value is obtained by calculating a first ΔPWM factor for the first zone, and using the first ΔPWM factor, in conjunction with a scaling factor, to weight a second ΔPWM factor calculated for the second zone.