Proton exchange membrane fuel cell is an emerging renewable energy resource for transportation and power generation. Similar to other renewable resources, the performance of proton exchange membrane fuel cell is affected by ambient conditions. However, procedures for analyzing the influences of such conditions on the performance of proton exchange membrane fuel cells are expensive and time-consuming. Moreover, the commonly used models have been developed on the basis of standard ambient conditions. Thus, these models are difficult to utilize under adverse ambient conditions. This study was performed to develop suitable proton exchange membrane fuel cell models that could reflect the effects of ambient conditions on the output voltage and current of the models. The first proposed model used the advantages of electrical and thermal relationships of a complex semiempirical model of a proton exchange membrane fuel cell. A simplified proton exchange membrane fuel cell model that used passive electrical components was then developed by central composite surface design. Both proposed models were simulated using various ambient temperatures, pressures, and load resistances by considering that the applied hydrogen pressure is known. Results showed that the output voltage of proton exchange membrane fuel cell decreased when ambient temperature increased and pressure decreased. This variation was dominant when the load resistance was reduced. Computation using the simplified model was remarkably faster than that using the first model. The proposed model can be beneficial, especially for aircraft applications and unusual ambient conditions.