ERA5 provides hourly estimates of a large number of atmospheric, land and oceanic climate variables. It combines vast amounts of historical observations into global estimates using advanced modelling and data assimilation systems. The initial release data, 5 days behind real time, is called ERA5T.
The data cover the Earth on a 0.25 degree grid for atmospheric parameters and 0.5 degree grid for wave parameters. It resolves the atmosphere using 137 levels from the surface up to a height of 80km. The data are also available on 37 pressure levels and on surface at hourly resolution.
The data include information about uncertainties (10 ensembles, ensemble mean and ensemble spread) at reduced spatial (0.5 degree for atmosphere, 1 degree for wave) and temporal resolutions (3 hourly data).
For more details please see: ERA5: data documentation