Abstract Offshore wind data derived from satellite measurements (CCMP, QuikSCAT, NCDC Blended Sea Winds and IFREMER Blended Wind Fields), reanalyses (NCEP-CFSR, ERA-Interim, NASA-MERRA and NCEP-RII), analyses (NCEP-FNL and NCEP-GFS) and WRF modelled offshore winds were compared to in situ measurements, in order to assess which one of these products is the best alternative to in situ offshore measured wind data. Wind speed and direction from these products were compared to measurements collected at five buoys moored along the Iberian Peninsula Atlantic coast. Results show that WRF modelled offshore winds are the best alternative to in situ measured offshore wind data, showing the highest temporal accuracy (the ability in representing the wind speed and direction at a given time instant) and lowest errors in terms of offshore wind power flux estimations. However, offshore wind data taken from CCMP shows the lowest errors in terms of the mean wind speeds and, together with IFREMER-BWF, the best wind temporal accuracy after WRF simulation. Therefore, in general CCMP and IFREMER-BWF can be considered as the best alternatives to WRF high resolution modelled offshore winds, if the latter is not available. Specifically for offshore wind energy resource assessment, NCEP-CFSR reanalysis or NCEP-GFS analysis data can also be used with confidence as an alternative to WRF modelled data, showing better wind power flux estimates than CCMP and IFREMER-BWF. Despite the best performances of WRF high resolution offshore winds, such modelling tasks require considerable computational resources and time to obtain quality results. Therefore, the value of satellite-derived wind data should not be disregarded. These remotely sensed offshore wind measurements should be seriously considered when searching for alternative sources of wind information for ocean areas, in particular for open ocean areas where they have their strength.