A wet afternoon and evening are expected at the Games.
Clouds bringing rain storms, some very heavy, are expected to move into London through the mid-afternoon. There is a chance they will stay to the south of the capital, but a wet afternoon is looking likely.
The evening does not look much better for the second session of the athletics, although the rain is not expected to be as heavy as the night draws in.
Heavy rain is expected in the early afternoon for the sailing in Weymouth, which will affect the men's and women's RSX medal races.
The North of Britain is expected to fare much better, with football in Manchester expected to avoid the worst of the weather.