The present study reports an experimental investigation regarding the dynamic characteristics of local current density in proton exchange membrane fuel cells during dynamic operation, important for mobile applications, by using segmented current collector method. The results indicate that for fully humidified operation, the local current density fluctuates more intensely when the cell potential is reduced, corresponding to an increase in the average cell current density (or load), whereas it is reduced considerably when the air stoichiometry is increased. Fluctuations in the local current density are lower near the flow channel inlet region and higher near the channel exit region. Operation at higher pressures enhances the cell performance, as expected, but results into severer fluctuations in the local current density. Further, it is observed that both the magnitude and the frequency of the fluctuations for the local current density are strongly influenced by the humidity condition in the reactant gas streams, and partially humidified operation results in significant fluctuations in regions near the channel inlet, suggesting close relation to the presence, distribution, and transport of water in the cell structure.