Can I Swim?

How this works

Every half hour, this site reads the official warnings for all 941 bathing waters in Britain and Ireland, and the live sewage overflow feeds for the 668 where one is published, and works out a single answer for each one.

How a verdict is decided

  • Do not swim today — somebody official has said so about this water: bathing is prohibited, a pollution incident is open, or a monitored storm overflow is discharging within 2km right now.
  • Advice against bathing today — an authority is advising against bathing here. That is sometimes today's pollution risk forecast, usually after heavy rain — a model's view of today rather than a measurement. But it is just as often a standing position that does not change from day to day: a bathing water classified Poor, where advice against bathing is posted for the whole season, or a Scottish beach where SEPA predicts poor water quality and warns against bathing. It sits below the level above because it is advice rather than a prohibition or sewage going into the water now.
  • Take care — the regulator forecasts increased pollution risk, or an overflow discharged nearby recently — in the last 48 hours, or 72 for Southern Water, whose feed uses a longer lookback — or heavy rain has fallen at a beach known to be affected by it.
  • No warnings today — the checks that could be made were made, and none of them found anything.
  • Can't say today — something could not be checked: a feed was down, a nearby overflow monitor was not reporting, or the bathing season has ended and the daily forecasts have stopped.

Two more words appear on the beaches nobody tests any more. Nobody tests this water means the beach was taken off the designated list, so there is no sampling behind it and there will not be a verdict. Advice against bathing on one of those pages is the Environment Agency’s standing instruction rather than anything about today.

    Each beach lists what was actually checked and what wasn't, so a green tick is never a bare assertion. Four rules the code holds to:

    • Never show green because something failed. A dead monitor, a feed that is down or a season that has ended all produce “can't say”.
    • An official warning outranks anything calculated here.
    • Last season's classification is not evidence about today's water. It can add a warning; it never earns a green tick on its own.
    • Say when, and say whether a number was measured or modelled.

    What it can't tell you

    • No live sewage spill feed exists in Ireland, north or south. Northern Ireland does monitor — NI Water had 466 event duration monitors by May 2026, covering 31 of its 33 designated bathing waters — but it publishes a summary once a year rather than live status, so nothing can say whether an overflow is discharging right now. In the Republic none is published at all. For Irish beaches this shows official notices and sample results only, and an empty spill list there is not a quiet one.
    • Scotland forecasts 30 of its 90 beaches. The rest have last year's rating and nothing about today.
    • The season ends. Daily forecasts and routine sampling stop on 15 September in Scotland, Northern Ireland and Ireland, and on 30 September in England and Wales. Out of season the site says so rather than showing green.
    • A monitor indicates a discharge, it does not confirm one. Every spill on this site comes from the water companies’ own event duration monitors, and they say themselves that those readings carry only provisional validation. Thames Water puts it plainly on its own map: this data “doesn’t confirm discharges, it only indicates them”. A monitor can be wrong in either direction, and a reading is a strong signal rather than a measurement of what is in the water.
    • Only monitored overflows appear. Unmonitored pipes, farm run-off, misconnected drains and boats do not. A monitor that has stopped reporting counts as unknown, never as clean.
    • Distance is not a model. A spill within 2km counts against a beach; tides and currents decide what actually reaches the water. Southern Water's own tidal assessment is used where they publish it.
    • Rainfall is modelled, from a weather model on roughly an 11km grid — not a rain gauge at the beach.
    • So are the sea state, the wave height and the sea temperature, from a marine model on a grid several kilometres across. There is no buoy at your beach, two beaches near each other often share one reading, and a bay behind a headland can be far calmer than the number says.

    Where the data comes from

    • Environment Agency — daily pollution risk forecasts, open pollution incidents, suspensions and classifications for England
    • Natural Resources Wales — Welsh classifications, and daily pollution risk forecasts for the Welsh sites that get one
    • SEPA — Scottish classifications and daily predictions
    • DAERA — Northern Irish sampling
    • EPA Ireland and local authorities — classifications and statutory bathing restrictions
    • Thames, Southern, South West, Wessex, United Utilities, Yorkshire, Northumbrian, Anglian, Severn Trent, Dŵr Cymru Welsh Water and Scottish Water — live storm overflow status for about 18,600 monitored outfalls
    • Environment Agency — the Event Duration Monitoring storm overflow annual returns, 2020 to 2025, which is where each beach’s yearly spill record comes from. England only
    • Open-Meteo — rainfall
    • RNLI — lifeguard unit locations. Contains Open Data licensed under the GIS Open Data Licence. Unit locations only: the data carries no patrol dates, so this site never says a beach is lifeguarded today, and never says a beach has no lifeguard, because these are the RNLI's own units and a council or surf club patrol is not among them.

    The code that collects it is public: Jay-1983/swim-collector.

    Putting it on your phone

    It works like an app once you add it — full screen, no address bar, its own icon on your Home Screen. There is nothing to download and no app store, because it is still just this website.

    iPhone and iPad

    1. Open this site in Safari. It has to be Safari — Chrome on an iPhone cannot do this.
    2. Tap the Share button: the square with an arrow coming out of the top. It is at the bottom of the screen, or top right on an iPad.
    3. Scroll down the list and tap Add to Home Screen.
    4. Tap Add, top right.

    Do this if you want to be told about your saved beaches. Apple only lets a website send notifications once it has been added to the Home Screen, so the switch on your saved places does not appear at all until you have. That is Apple's rule and there is nothing this site can do about it.

    Android

    1. Open this site in Chrome.
    2. Tap the three dots, top right.
    3. Tap Add to Home screen, or Install app if you see that instead.
    4. Tap Install.

    Either way it keeps itself up to date, so there is never an update to install. Pages you have already opened will still open with no signal — but the readings will not be today's, and it says so rather than showing you yesterday's answer.

    This is not an official source

    It reads published data and presents it plainly. It is not a substitute for the regulator, the water company or a sign at the beach. If a sign says otherwise, believe the sign. Nothing here is advice about whether you personally should swim.