The Big Brenig Swim

About the Event

Set against the backdrop of Llyn Brenig, near Cerrigydrudion in North Wales, The BIG Brenig Swim is an open water swimming adventure that draws enthusiasts and novices alike. Located within Conwy County, this picturesque lake offers a serene setting for swimmers to challenge themselves.
The centerpiece event features a 2.5km swim across two widths of the expansive Llyn Brenig, starting from beside the visitor center. For those seeking an extended challenge, there's also a grueling 5km option that involves completing four laps around the lake. Additionally, shorter distances are available for swimmers looking to dip their toes in: a 1km swim and a half-kilometer splash. The latter two options welcome children aged six and older when accompanied by an adult who has paid entry fees.
Swimming conditions vary based on water temperature; wetsuits will be mandatory if the lake's surface falls below 15 degrees Celsius, ensuring safety for all participants regardless of their preference or experience level.
The swim course is linear, marked with inflatable buoys to guide swimmers along both directions. A cut-off time of three and a half hours applies across all distances, maintaining an orderly flow throughout the event.
For junior entries aged 12-15 years old, they can participate in either the 500m or 1km swims but must be accompanied by a paying adult who will take full responsibility for their safety. Wetsuits and tow floats are compulsory for these young swimmers to ensure an enjoyable yet secure experience.
Entry fees include access to all distances based on your preference, whether you opt for wetsuit or non-wetsuit conditions (non-wetsuit participants must use a swimming tow float). It's important to note that refunds and deferrals are not available once registered. However, the event offers an optional XCover insurance policy that provides a refund if unforeseen circumstances prevent your participation.
Before signing up, make sure you read through all terms and conditions thoroughly for a clear understanding of what’s expected from participants. This ensures everyone is prepared to embrace the unique beauty and challenges Llyn Brenig has to offer during The BIG Brenig Swim event.

Races Offered

1.5km (Juniors 12-15)

Sep 12, 2026

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Distance — 1.5K

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Type — Water sports

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61 days remaining

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£58.00

1km

Sep 12, 2026

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Distance — 1K

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Type — Water sports

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61 days remaining

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£68.00

2.5km

Sep 12, 2026

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Distance — 2.5K

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Type — Water sports

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61 days remaining

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£79.00

500m

Sep 12, 2026

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Distance — 500m

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Type — Water sports

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61 days remaining

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£50.00

500m (Juniors 12-15)

Sep 12, 2026

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Distance — 500m (Juniors 12-15)

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Type — Water sports

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61 days remaining

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£45.00

5km

Sep 12, 2026

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Distance — 5K

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Type — Water sports

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61 days remaining

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£90.00

Weather History

These values represent the 3-year monthly averages for September in Conwy.

thermostat Temperature

9.9° / 15.8°

wb_sunny Feels like

7.4° / 13.5°

light_mode Avg sunshine hours

6h 35m

water_drop Avg rainfall

4.9 mm

ac_unit Avg snowfall

—

air Avg wind speed

12.8 km/h (Gentle breeze)

opacity Sweat loss rate

Low

terrain Course conditions

Firm and slightly soft

sunny Max UV Index

Moderate (3.5)

humidity_mid Humidity

85.9%

wb_twilight Sunrise

06:49

nightlight Sunset

19:29

About Conwy

Learn more about the host city, Conwy.

Conwy is a small walled town on the coast in North Wales. It is on the UNESCO World Heritage List and a perfect base for exploring everything North Wales has to offer. The gateway to Snowdonia and easy access to the Island of Anglesey, the Victorian seaside town of Llandudno and the timeless Llyn Peninsula.