An environmental parameter sensor for a mobile device is described comprising a first acoustic transducer; a second acoustic transducer arranged at a predetermined distance from the first acoustic transducer; a controller coupled to the first acoustic transducer and the second acoustic transducer; wherein the controller is configured to determine at least one of a time-of-flight value and an attenuation value of an acoustic signal between the first acoustic transducer and the second acoustic transducer and to determine at least one environmental parameter from the at least one of the time-of-flight value and the attenuation value The environmental parameter sensor may determine environmental parameters such as temperature, wind speed, and humidity from acoustic measurements.