Duplicate fields in hourly ERA5 thermal radiation download

[rcomer]

What happened?

Downloading hourly data for 2014, I get duplicate times for 2014/01/31 and 2014/02/01.

What are the steps to reproduce the bug?

Download script:

import cdsapi

C = cdsapi.Client()

C.retrieve(
    'reanalysis-era5-single-levels',
    {
        'product_type': 'reanalysis',
        'variable': 'top_net_thermal_radiation',
        'date': '2014-01-01/2015-01-01',
        'grid': '2.5/2.5',
        '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',
        ],
    },
    'test.grb')

grib_ls test.grb shows that there are 31 fields for 31st January and 37 fields for 1st February. Each should have 24 fields.

$ grib_ls test.grb | grep 20140131 | wc -l
31
$ grib_ls test.grb | grep 20140201 | wc -l
37

I have reproduced this three times. I attempted to reproduce by requesting a smaller number of days around the problem dates

• 'date': '2014-01-31/2014-02-01'
• 'date': '2014-01-30/2014-02-02'
• 'date': '2014-01-01/2014-02-28'

but in all these cases, I got the correct number of fields. I have also run the equivalent download with each year from 1991 to 2013 with no problems.

Version

v0.7.7

Platform (OS and architecture)

RHEL9

Relevant log output

Accompanying data

No response

Organisation

Met Office