I've checked the BBC's Five Day Forcast, and they say it's going to be sunny all the way in London!! Woo Hoo! Temperatures of 20 degrees C (68 F), though it will feel a little cooler due to the wind which will be coming from an easterly or north easterly direction. But no rain, which is always good when it comes to queuing.
http://www.bbc.co.uk/weather/5day.shtml?world=4581 Though I suspect that the predominant weather condition in London over the next three days and then moving northwards over the weekend will be
JAMES FOG