Systems, methods and devices for nitric oxide generation are provided for use with various ventilation and/or medical devices and having a humidity control system associated therewith. In some embodiments, a system for generating nitric oxide comprises at least one pair of electrodes configured to generate a product gas containing nitric oxide from a reactant gas, a scrubber configured to remove nitric dioxide NO2 from the product gas, and a humidity control device configured to alter a water content of at least one of the reactant gas and the product gas to control humidity within the system.