Olympic events have been plagued by bad weather as showers left spectators in the main park drenched and caused a controversial delay in the equestrian.
Heavy rain swept across the main site and the equestrian venue in Greenwich, south east London.
A ten-minute delay, which New Zealand's Andrew Nicholson branded "an absolute disgrace", was enforced during the dressage due to bad weather.
Briton Kristina Cook remained philosophical after competing during a downpour just before the delay while team-mate Zara Phillips managed to enjoy the best of the weather earlier, watched by the Princess Royal and the Duke of Edinburgh in dry and bright conditions.
Swede Niklas Lindback had gone in to the arena in the afternoon but was told to wait amid thundery showers. Nicholson, who followed him, said of the delay: "It was a disgrace, an absolute disgrace. I thought the British were meant to be sporting people. I'm serious.
"They didn't mind the thunder and the lightning and the rain earlier, and then suddenly it's a ten-minute delay. I messed up a couple of bits which are normally my best bits because he felt like he was a little bit switched off. To me, the weather wasn't bad enough to warrant that, it's just a bit of rain isn't it?
"I'm very frustrated with the organisers, I'd expect more from them at an Olympic Games."
The venue also saw problems with the roof on the judges' building coming loose in the wind.
After her test, Cook said: "I'm used to riding him in the rain at home, I don't have an indoor school. I've ridden in some very wet days on the South Downs. The horse is used to that to be honest, that side of it he was great. But when the judges' roof came up and down as he was doing his extended trot I really hoped that he wasn't going to spook.
"I'm just really pleased and proud of the horse that he just really kept a lid on it and kept focused and tried his best. Obviously I would love the sun shining down on me now, it would have been brilliant, but that's England for you isn't it?"