The combined influence of factors, that is, operating cell temperature, humidification temperature (HT) (indirectly relative humidity), and reactant gas inlet‐line temperature on the performance of proton exchange membrane fuel cell was experimentally and statistically studied. A catalyst‐coated membrane, membrane electrode assembly, of 6.25 cm 2 active area and 0.29 mg pt cm –2 catalyst loading was used in the study. Experimentally, the effect of individual factors and their combinations on cell performance was studied. Statistical analyses were carried out to find the main and interaction effects of different factors. Analysis of variance (ANOVA, 5% significance level, 95% confidence level) analysis, which was validated for homoscedasticity, was used to evaluate the significance of the main and interaction effects of factors. From the study, it was observed that the HT had a significant main effect (988 W m –2 ). Both interaction plots and ANOVA results revealed that the combination of operating cell and HT was the most significant. The study showed a very interesting observation that the statistical interaction effect (545 W m –2 ) was half of the experimental deviation value (1090 W m –2 ) between the summation of independent effects and the combined effect.