Mr Johnson was at Putney Pier, declaring the rain had passed as he geed-up the crowds around him.
“I want you to know the rain has stopped, hasn’t it?” the politician said, turning to a crowd behind him while being interviewed by BBC News.
He added: “It’s going to be a fantastic day, I’ve no doubt about that at all.
“We’re are looking forward very much here in Putney to the kick-off, which I think is in a couple of hours time, but already the crowds are enormous here.”
He added: “It’s an amazing thing, this is only the second time in the country that a monarch has reigned for 60 years.
“This is a chance for people to come to London, look at this jubilee pageant and pay tribute to the Queen for 60 years of amazing service to her country.”
by Arthur Furrowfield