The influence of environment during device fabrication and measurement conditions are critical issues to realize efficient perovskite solar cells on large scale and push the industrial development. In this work un-encapsulated methylammonium lead iodide perovskite solar cells were fabricated and characterized in different relative humidity environment and the effect on the performance metrics of voltage pre-bias and scan rate were analyzed. The value of short-circuit current density estimated from characteristic curves and calculated from external quantum efficiency spectra are compared. A preliminary measurement procedure was proposed. The best solar cells were obtained by fabricating the devices at 40% relative humidity and changing the dopants of hole transport material reaching 12.6% of power conversion efficiency.