London has around a dozen places to swim outdoors: Victorian lidos, natural bathing ponds, a reservoir and a purpose-built lake. Prices run from £5 for a pond swim on Hampstead Heath to about £9.50 for a 50-metre lido. Some are heated and open all year, some are freezing and open all year, and two of them are single-sex.
The differences matter more than the prices. A heated 50-metre pool at 24 degrees in December and an unheated pond at 4 degrees in December are not the same activity, and quite a few visitors arrive at the second expecting the first. Booking rules vary too: one place has suspended online booking entirely until spring 2027, another requires an induction and a red hat before it will let you in the water.
This guide sets out which is which, what each costs, and what you need to know before you get in.
| Where | What it is | Heated? | Season | Adult price (Sept 2026) | Booking |
|---|---|---|---|---|---|
| Hampstead Heath ponds | Three natural bathing ponds | No | Men's and Ladies' all year; Mixed April-October | £5.00 | Suspended until spring 2027; pay on arrival |
| Parliament Hill Lido | 60m unheated chlorinated pool | No | 365 days a year | £5.00 winter; £8.80 summer morning or afternoon | Suspended until spring 2027 |
| Brockwell Lido | 50m outdoor pool | No | All year | £9.50 (child £6.00) | Yes, through Active Lambeth |
| Tooting Bec Lido | 91m freshwater pool, the UK's largest | No | Summer season for the public | Check the operator | Advised, non-refundable |
| London Fields Lido | 50m floodlit pool | Yes, about 24C | All year, 06:30-21:00 daily | Check the operator | Advised |
| Charlton Lido | Heated 50m pool plus teaching pool | Yes | All year | Check the operator | Yes, online or app |
| Serpentine Lido, Hyde Park | 100m roped area of the lake | No | Roughly June to mid-September | £8.40 full day, £6.50 session, £2.50 after 4pm | Recommended, not essential |
| West Reservoir, Hackney | Open water in a working reservoir | No | Check the timetable | Check the operator | Yes, plus an induction |
Heated or unheated: the one thing to check
Only two of London's outdoor pools are heated: London Fields Lido in Hackney and Charlton Lido in Greenwich. Both are 50 metres and both are open all year. London Fields runs at around 24 degrees, which is warm enough to swim lengths in comfortably in January, and it is floodlit, which matters when it is dark by four in the afternoon.
Everything else is at whatever temperature the weather has left it. Parliament Hill Lido, Brockwell Lido and Tooting Bec Lido are all unheated, and the ponds and the reservoir are natural water. In midsummer these sit in the high teens or low twenties. In January they can be close to freezing.
Several operators now publish a live water temperature on their own websites, including Tooting Bec and Brockwell. Check it on the morning of your swim, not the week before.
Brockwell Lido will not let children in below 15 degrees. Junior swimmers are only permitted when the water is at 15C or above, which in practice rules out roughly half the year. If you are bringing children to an unheated lido, check the live temperature before you travel, or book a heated pool instead.
Photo: Bloodholds · CC BY-SA 4.0 · Wikimedia Commons · resized
The bathing ponds on Hampstead Heath
The three natural ponds on Hampstead Heath are the most distinctive place to swim in London and much the most heavily regulated. Our Heath guide works through the pond-by-pond seasons, the child restrictions and the cold-water rules; what follows is the short version you need in order to plan.
- Kenwood Ladies' Pond and Highgate Men's Pond are single-sex and take swimmers in every month of the year.
- The Mixed Pond operates in spring and summer only.
- Prices: £5.00 for an adult, £3.00 on the concession rate, which covers anyone below 16.
- Minimum age 8, with a strict supervision ratio and a compulsory swim test for every newcomer under 16.
- Dark, deep water with no shallow end. These are ponds for confident swimmers, not for a paddle.
Two changes in 2026 affect everybody. Online booking shut down in early September and will not return before next spring, so you now queue and tap at the gate instead. And from 1 October 2026 card or phone becomes the only way to pay at every City of London swimming site, with no cash accepted. Our page on paying by card in London covers what to check with your bank first.
Parliament Hill Lido
If the ponds sound like too much, there is a 60-metre unheated chlorinated pool on the Parliament Hill flank of the Heath, open on all 365 days, with hot showers and a sauna through the winter. Children who do not get through the pond test are allowed in here instead.
A winter single costs £5.00 for an adult, £3.00 on concessions and £1.50 for juniors aged 5 to 15. Summer morning and afternoon sessions rise to £8.80 for an adult, while breakfast and evening sessions stay at £5.00. Anyone under 16 or over 60 who can show proof of age gets in for nothing before half past nine in the morning, at the pool and at the ponds alike. The cashless rule and the booking suspension apply here too.
The Serpentine Lido, and why it shuts
The Serpentine Lido is a marked 100-metre stretch of open water at the south-western corner of the lake in Hyde Park, with lifeguards and a café, and it is the only place in any of the Royal Parks where public swimming is allowed at all.
Public swimming runs in summer only. The Royal Parks describes the season as usually June to mid-September, with weekend sessions from mid-May, and does not publish exact dates in advance. An adult full-day ticket is £8.40, a session £6.50, and entry after 4pm just £2.50. Booking is recommended rather than required, and under-16s must swim with an adult.
One warning about searching for it online: the domain serpentinelido.com is a parked page and is not the official site. Book through the Royal Parks instead.
Brockwell, Tooting Bec and the south London lidos
South London has the two most impressive Victorian and inter-war pools in the city.
Brockwell Lido, on Dulwich Road at the edge of Brockwell Park, is a 50-metre outdoor pool built in 1937 and listed Grade II. An adult swim is £9.50 and a child £6.00, and it is open all year, including a Christmas Day swim at £12.00. There is a gym, a sauna and steam room and a café on site, and a swim-only winter season membership was on sale at £140.
Tooting Bec Lido, on Tooting Bec Road, is the largest freshwater outdoor pool in the United Kingdom at 91 metres. It is unheated, with a children's paddling pool, a café and a sunbathing area, and it publishes a live pool temperature. Public opening is seasonal: it reopens for the spring and summer season, in recent years from the start of May. The operator asks swimmers to book ahead to guarantee a space and states that bookings are non-refundable.
The two heated pools that are open in January
London Fields Lido sits in London Fields park in Hackney, a short walk from London Fields and Hackney Downs stations and from Broadway Market. It is a 50-metre heated, floodlit outdoor pool, open Monday to Sunday from 06:30 to 21:00, with lane swimming daily. In September 2026 the water was at 24 degrees. The address is London Fields West Side, E8 3EU.
Charlton Lido, in Hornfair Park on Shooters Hill Road in Greenwich, is the other: a heated 50-metre outdoor pool that swimmers use all year, with a separate teaching pool, a gym and floodlit tennis courts. Book online or through the operator's app before you go.
These two are the answer if you want to swim outdoors in London in winter without it being an ordeal. The indoor alternative, and a fine one, is the 50-metre pool at the London Aquatics Centre built for the 2012 Games.
Open water: a reservoir and a lake
Two places in London offer open-water swimming as a sport rather than as a dip.
West Reservoir Centre at Woodberry Down, on Green Lanes, N4 2HA, is a working reservoir a short walk from Manor House station, run as a water sports centre with Royal Yachting Association sailing and kayaking alongside the swimming. First-time swimmers must do a short induction with the staff, and red swim caps are compulsory in every session. Booking is through the operator's app, and the centre opens from 07:00 to 20:00. It is a short walk from Stoke Newington.
Beckenham Place Park in Lewisham has a purpose-built swimming lake, run under a concession for the council, open for pre-booked swimming sessions. Check Lewisham Council's park pages for the current season, session times and prices before travelling.
Where you must not swim
This matters, because London has a great deal of water that looks swimmable and is not.
- The Royal Parks lakes. Swimming is banned in every lake and pond in the Royal Parks. The Serpentine Lido, with its lifeguards, is the only exception.
- Epping Forest. The City of London states that the ponds, lakes and rivers there are not safe for swimming, citing hidden hazards, cold water shock and unmonitored water quality. Our guide to Epping Forest has the detail.
- Park boating lakes. The lakes at Victoria Park, Battersea and elsewhere are for boats, not swimmers.
- The Thames in central London. Tidal currents, shipping and water quality make this dangerous.
- Any pond with a blue-green algae warning. These appear on the Heath and elsewhere in warm weather, and the toxin is particularly dangerous to dogs.
Cold water, and the official advice
The City of London publishes cold-water guidance for swimmers at its Hampstead Heath facilities. Broadly, it warns about the risks of hypothermia and of cold water shock, advises anyone new to winter swimming to increase their exposure gradually rather than all at once, tells swimmers not to dive into cold water, and recommends re-warming slowly afterwards rather than with a hot shower.
We are not in a position to give medical advice, and nor is any travel guide. Read the operator's own guidance on the day, follow what the lifeguards tell you, and if you have a heart condition or any other relevant health problem, ask a doctor before swimming in cold water. Our page on healthcare for visitors explains how to get medical help in London if you need it.
What to take
- A towel and a change of clothes. Very few of these places sell towels, and none of them hires them out.
- A card or phone, not cash. The City of London's facilities are cashless from 1 October 2026 and most other operators prefer card.
- A swim hat. Compulsory at West Reservoir, where it must be red, and useful everywhere in cold water.
- Flip-flops for the walk from changing room to water, which at an unheated lido in winter is the worst part.
- Something hot to drink for afterwards, and a warm hat. Most sites have a café, but not all of them open early.
- Proof of age if you are claiming a concession or a free early swim.
Our guide to what to pack for London covers the rest, and the weather month by month will tell you how optimistic to be. On a day when swimming outdoors is clearly a bad idea, our list of indoor places for children has the alternatives, and outdoor swimming at these prices still counts among the best cheap things to do in London.
Frequently asked questions
Where can you swim outdoors in London?
The main options are the three bathing ponds on Hampstead Heath, Parliament Hill Lido, Brockwell Lido, Tooting Bec Lido, London Fields Lido, Charlton Lido, the Serpentine Lido in Hyde Park, West Reservoir in Hackney and the swimming lake at Beckenham Place Park. Only London Fields and Charlton are heated.
How cold is the water in London's lidos?
The heated pools at London Fields and Charlton stay comfortable all year, with London Fields around 24 degrees. Every other outdoor pool and pond in London is unheated, so the water follows the air temperature: warm in July and August, and close to freezing in January and February. Several operators publish a live water temperature on their websites.
Which London swimming ponds are single-sex?
Two of the three on Hampstead Heath: the Kenwood Ladies' Pond and the Highgate Men's Pond, both of which take swimmers in every month of the year. The third, the Mixed Pond, admits everybody but operates in spring and summer only.
Do you have to book to swim at a London lido?
It depends. Brockwell, Charlton, London Fields and Tooting Bec all take bookings and advise them, especially at weekends. West Reservoir requires a booking and a first-time induction. The Hampstead Heath ponds and Parliament Hill Lido have suspended online booking until spring 2027, so all swims there are paid for on arrival.
Can children swim in the Hampstead Heath ponds?
Only from their eighth birthday, and then only under close supervision: one adult may bring no more than two young swimmers, and every newcomer under 16 is tested in the water before being allowed to use the pond properly. Parliament Hill Lido is the easier option for families, at £1.50 for a junior swim in winter.
Is it safe to swim in London's lakes and rivers?
No, except at the supervised sites listed above. Swimming is banned in the Royal Parks lakes apart from the Serpentine Lido, and the City of London warns that the ponds, lakes and rivers in Epping Forest are unsafe because of hidden hazards, cold water shock and unmonitored water quality.
Sources
- City of London Corporation - Booking for swimming at Hampstead Heath (checked September 2026)
- City of London Corporation - Swimming tickets and prices (checked September 2026)
- The Royal Parks - Swimming at the Serpentine Lido (checked September 2026)
- Active Lambeth - Brockwell Lido (checked September 2026)
- Places Leisure - Tooting Bec Lido (checked September 2026)
- Better - London Fields Lido (checked September 2026)
- Better - Charlton Lido and Lifestyle Club (checked September 2026)
- Better - West Reservoir Centre (checked September 2026)