This is the ERA5 dataset that can be used to calculate air density for wind energy purposes using the equations presented in https://doi.org/10.3390/en12112038. The NetCDF file contains mean fields of monthly means from 2010 to 2020 of the variable temperature, surface pressure, specific humidity and the lapse rate. The horizontal grid resolution is 0.25 degrees and covers the whole globe. These fields are used in the WAsP software version 12.6 and above to calculate the air density at specified heights above mean sea level. The WAsP software (www.wasp.dk) is the industry standard method to calculate the annual energy production of wind farms. The ERA5 data are generated using Copernicus Climate Change Service information [2020]