A remote sensor system (60) and method for passively sensing environmental conditions, such as temperature and humidity, uses a magnetic impulse from an AC interrogation coil (68) to stimulate a magnetoelastic sensor (62) to generate an acoustic signal (AE) at the resonant frequency of the magnetoelastic sensor (62). The acoustic signal (AE) is received by amplifier (74), detected and displayed (76). The systems and methods are particularly suited for detecting environmental conditions in commercial pharmaceutical packaging, such as blister packs.