South of the M4 is near london, france :p
Not entirely sure your question is serious but anyway, we’ve just been out. Is hovering around the 2 dec C mark at the moment. For today’s commute I wore my roubaix bib longs over lycra, with endura shorts to make sure I didn;t get the lady car commuters too excited, and a roubaix jersey, with a string vest underneath and a goretex jacket. I was comfortable in that at 7am and a tad warm at 5pm, but would probably be right for a 7pm ride
Alternatively, I have in the garage 2 bottles of wainwright (mine, all mine I tell you), some Banks’s, and two larger bottles of Leffe (one blonde, one brun) that probalby need to be drunk as they’re past due date. With you being from france you might fancy some leffe? 🙂