A self-referencing, microelectromechanical system with dual mechanical modes for temperature independent environmental sensing including a resonator configured to resonate in a first fundamental width extensional mode and in a second contour mode, including: an input port; an output port; a top electrode comprising an aluminum chromium layer; a silicon-oxide layer; an aluminum-nitride layer; and an RF ground comprising a silicon layer. Upon passing a signal to the top electrode of the resonator, the top electrode and the RF ground establish an electric field to enable transduction through the piezoelectric, aluminum-nitride layer, and the resonator has adjacent contour modes close in frequency such that mechanical resonances of the resonator in differing resonance modes shift together as a function of temperature, the simultaneous shift of the mechanical resonances remaining constant across the temperature range enabling sensing of various criteria.