You are right Chris.. even my "magical" forecast ( BBC) is now showing possible showers.
Although it doesn't look too bad as forecasts go:

It has been showing totally sunny and warmer until today.
The cooler temperature I don't mind , it can be too hot for comfort, which it was a year or two back .
A member of the public collapsed with heatstroke and there was a mini drama getting the medics into him.
With such big crowds there is a claustrophobic element that only seems worse in high temperatures.
At such times I am glad of the cool open space inside the East Wing of my Booth
