The Olympics are just over two weeks away, but there are real fears that the biggest sporting event in the World could become a complete washout.
The downpours, that have ruined the summer of 2012 so far, are beginnning to cast doubt over whether there's a plan in place to cope with the wet weather.
Fifty thousand people a day are expected to go to Hyde Park to watch the games on the Big Screen, but already one big concert has already been cancelled. Simon Harris looks at whether the weather will ruin the games.
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As disruption continues throughout the evening here's what you need to know
Fallen trees, damaged power lines and emergency speed limits were today causing chaos for rail passengers.
They will be supported by artists including Zara Larsson, G-Eazy, Wiley, Sean Paul, WizKid and an exclusive set from Bryson Tiller.