Download ERA5 reanalysis from the climate data store

This video demonstrates how to register on the European Union Copernicus climate data store, which is a product of the Copernicus Climate Change Service (C3S) hosted at the European Centre for Medium Range Weather Forecasts (ECMWF).
I will show you how to find the ERA5 reanalysis data or climate observations that you may require, and then proceed to downloading the netCDF (or grib) files directly to your computer in using the web interface.
The explanation is aimed at beginners with no prior knowledge of the system.