At midnight in SYNOP reports the total of the previous incoming net solar radiation is reported (or so I think). Many countries report it at this time, others like the French don’t just to be awkward. Here are the values from yesterday across the UK and the near continent (fig 1). I’m not overly clear about the values that I’m displaying or the units I’m using because the WMO manual is suitably vague, and I don’t know what typical daily values to expect at this time of the year. If you know exactly what these totals are please drop me a comment.