ERA5 data December 2023

Hello, I have been downloading monthly data from ERA5 for the area of Germany without any problems. However, I recently downloaded the data for the month of December 2023 and found the file filled with NaN values, although the previous months contain values without any problems. Also, the file size is approximately double the usual size compared to previous months.

Is there any explanation for this?

Here is the request:

    import cdsapi
    c = cdsapi.Client()
    c.retrieve(
               'reanalysis-era5-single-levels',
                {
                    'product_type': 'reanalysis',
                    'format': 'netcdf',
                    'variable': [
                                            'total_sky_direct_solar_radiation_at_surface',
                                            'surface_solar_radiation_downwards',
                                            'surface_net_solar_radiation',
                                            ],
                    'year': '2023',
                    'month': '12',
                    'day': [
                                    '01', '02', '03',
                                    '04', '05', '06',
                                    '07', '08', '09',
                                    '10', '11', '12',
                                    '13', '14', '15',
                                    '16', '17', '18',
                                    '19', '20', '21',
                                    '22', '23', '24',
                                    '25', '26', '27',
                                    '28', '29', '30',
                                    '31',
                        ],
                    'time': [
                                    '00:00', '01:00', '02:00',
                                    '03:00', '04:00', '05:00',
                                    '06:00', '07:00', '08:00',
                                    '09:00', '10:00', '11:00',
                                    '12:00', '13:00', '14:00',
                                    '15:00', '16:00', '17:00',
                                    '18:00', '19:00', '20:00',
                                    '21:00', '22:00', '23:00',
                                    ],
                    'area': [59.0, 4.0 ,40.0, 17.0],
                    'grid': [0.025, 0.025],
                },
                'output.nc'
                )

Thank you in advance!

Hi Omar,
The December 2023 data probably currently contains a mixture of ERA5 and ERA5T data, leading to an extra dimension (expver) in the netCDF file. See this post for details and workarounds

Hope that helps
Kevin