So it’s midday and already 32.5’C in Reading. 34’C has been recorded in parts of London. 35’C looks likely, if not 36’C.
There will be a bit more cloud around from 2pm, and one or two scattered thunderstorms should break out. I still think no higher than a 20% chance of one.
Interestingly lightning is more likely than heavy rain, as any rain may evaporate before it lands, should we catch a thunderstorm. That said, there is still a chance of torrential downpours, and possibly hail. Overall no higher than a 20% chance that we catch a thunderstorm, I’d suggest 3pm to 5pm the most likely slot, though evening also possible.