I may be wrong, but I would have thought a sea fret would have been coastal, mostly south of the downs - as I said earlier, when I went through at 6:30 it stretched right up to Gatwick, then suddenly cleared.
Yes, it was. Interestingly, when I got off the train back in Shoreham last night, although it was still clear blue sky, the air temp was far lower than it had been in London.
Travelling up this morning on the train, there was 50 yards vis with fog up to Gatwick - completely sunny and hot there-on upwards to Londinium Town. Looks quite lovely out the window in the city.