If you're passing by the Serpentine in Hyde Park on Saturday 19 September 2026, you won't be able to help notice that the water's inundated with brightly coloured swimming caps.
This is Swim Serpentine, an annual event in which some 6,000 swimmers, aged between 10 and 86, take to the chilly waters to swim a variety of distances, between half a mile and six miles.
Hardy participants do the Serpentine Swim as part of the London Classics, meaning they also compete in the London Marathon and RideLondon 100 in the same year (though as the latter is on indefinite pause, competitors can replace it with the Etape Loch Ness instead) .
All slots for 2026's event — which you can watch as the swimmers set off in waves between 8.15am and 4.50pm — are now sold out via the Swim Serpentine website. However, you may still be able to get a spot via a charity.
Otherwise, head to the banks of the Serpentine on Saturday, and cheer on participants. (The Serpentine Bridge is a particularly good spot for spectating.) Maybe it'll even inspire you to sign up for next year's event.
Swim Serpentine, Saturday 19 September 2026, free to watch.
