High frequency concomitant voltage and pressure measurements on a single proton exchange membrane fuel cell are presented in this paper. Voltage, anodic and cathodic pressure measurements were shown to be highly sensitive to gas relative humidity and temperature of the cell. Fast voltage dips corresponding to pressure spikes at the anode were observed and indicate a flooding occurrence due to the blockage of anode inlet by liquid water. In a generalize flooding of the cell, pressure drop fluctuations are easily recognizable and result in voltage fluctuations and drift. A methodology based on short‐time analysis on both, voltage and pressure signals, is used to quantify the effects of flooding and drying within proton exchange membrane fuel cell (PEMFC) systems. Intermittent behavior is highlighted on the standard deviation of the voltage for flooding and drying cases. Simultaneous analysis of the standard deviation short‐time for voltage and pressure signals allows for the differentiation between flooding and drying cases. Concomitant pressure and voltage fluctuations can be easily detected and monitored for a reliable diagnostic of proton exchange membrane fuel cell systems.