Breeze likely to be coming from a southerly direction, so hopefully not cold. Last thing you want is an easterly or north-easterly wind on an already fairly cool day. Hopefully it'll be a day of quality over quantity, with plenty of fun people out to enjoy themselves.
The down side of London is that many seem tense. Hardly surprising given the vast packs of iPhone idiots and the kamikaze drivers all over the place. I saw cyclists actually being driven at last year coming down The Mall

I've covered London four times now and never got a set of pics I'm happy with it. Every time I vow never to do it again, then when it comes round I foolishly think this year it might be a good one. Eternal optimist
Ride departs Hyde Park at 3pm. Last year it took barely two hours to complete. Compared to 2012, when it took more than four hours and the ride brought central London to a standstill.