An automatic window tinting system for a vehicle includes a selectively transparent window, a controller including a processing unit and a non-transitory computer readable memory, a temperature sensor, an occupant sensor, a proximity sensor, and a computer readable and executable instruction set. The computer readable and executable instruction set causes the processing unit to receive an occupant sensor signal, a temperature signal and a proximity sensor signal, maintain the selectively transparent window in a first light transmissivity state when the occupant sensor signal is indicative of a presence of an unattended occupant, transition the selectively transparent window to a second light transmissivity state when the temperature signal is indicative of a temperature inside the vehicle that is greater than a threshold value, and transition the selectively transparent window to a third light transmissivity state when the proximity sensor signal is indicative of the presence of a passerby.