Thousands of people are taking part in the London to Brighton bike ride, starting from Clapham Common.
The British Heart Foundation, which organises the fundraising ride, said that about 14,000 riders were due to tackle the 54-mile route.
The first cyclists were due to start at 6am, with the last ones setting off at about 9.30am, and they will all be heading for Brighton seafront where the ride ends.
The charity said: “This year will be BHF’s London to Brighton Bike Ride 45th anniversary. The charity hopes 2022 will raise more than £2.8 million.
“Among the riders will be Jason Cooper, the drummer of British rock band the Cure.
“Jason will ride in memory of Paul ‘Ricky’ Welton, a long-time member of the Cure crew and Jason’s drum tech, who tragically died shortly after suffering a heart attack on the Cure’s last tour in 2019.
“Jason will be joined by a team of riders for the event, cycling to raise money in Ricky’s name and to help the BHF’s lifesaving research into heart and circulatory diseases.”
The British Heart Foundation also said: “For the first time ever, we’re working with a number of other charities who will have riders in the event.
“Charities involved in the event will be present along the London to Brighton route and at the finish line.”
And the BHF added: “There are plenty of rest points and refreshment points on the route.
“Ditchling Beacon is the last climb of this great event. Situated seven miles before the finish line, with an elevation of 248m, it is the highest point in East Sussex.
“Once you reach the top, the views of Brighton are fantastic and well worth stopping at as this is the last refreshment point before the finish line.”
The weather promises to be damper and cooler than some years, with sunshine more likely as the day wears on.