It's a brilliant tradition that really shakes off the festive cobwebs, but this year many of the Christmas and New Year swims and dips won't be happening - or they will go virtual.
They raise loads of money for charity and are loads of fun, so it's a shame that the events won't be as usual this Christmas due to the ongoing coronavirus pandemic.
Here are the latest details on what we know about the main events around Wales.
We'll update this article as more announcements are made but if you have details you'd like us to include, please email kathryn.williams@walesonline.co.uk
Porthcawl
Organisers of the Christmas Day Porthcawl swim, which will celebrate its 56th anniversary this year, have already said that the swim will go ahead - but with a difference.
Instead of the mass gathering on the seafront on December 25, participants are invited to 'splash for cash' throughout December.
On its Facebook page, organisers wrote: "We are going virtual AND global! The Covid-19 rules mean we can’t have a mass swim at Sandy Bay, but we aren’t going to give up on one of Porthcawl’s finest traditions.
"In 2020, we invite you to make a 'Splash for Cash' in aid of Wales Air Ambulance and other local charities and organisations.
"You can do this wherever you are in the world on any day from the 1st to the 25th December."
Find out the latest at christmasswim.org
Lido Ponty
Sadly due to damage done by Storm Dennis in February, the Lido won't be open until at least Easter 2021.
The lido usually puts on a Boxing Day swim.
Tenby
Organisers have reluctantly put their 50th anniversary Boxing Day event on hold - but there could be light at the end of the shore as they are planning a May Day Dip instead.
This is subject to safety guidelines at the time, of course, and harks back to Tenby's Dunking Day - when locals got the holiday season underway by going for a sea swim,
Keep up to date with the plans via www.tenbyboxingdayswim.co.uk and Tenby Boxing Day Swim on Facebook.
Pembrey
The Boxing Day Walrus Dip at the Carmarthenshire country park has cancelled the swim at Cefn Sidan beach for only the third time in its 34-year history.
Cllr Peter Hughes Griffiths, a member of the Carmarthenshire County Council's Executive Board for Culture, Sport and Tourism, said: "We are extremely disappointed that we have had to cancel the Season's Dip. It's a very popular event and I understand that many people will be disappointed, but considering the current situation regarding the Covid-19 pandemic we have no choice. I hope people will find other ways to give generously and support good causes in our communities."
Abersoch
In Abersoch, the New Year's Day Dip has been cancelled as organisers, the local RNLI, have no option under current guidelines.
They wrote: "We know that many of you support this fun event and will be disappointed, but for the safety of everyone and to comply with local Covid restrictions we have no option to cancel the dip this year. We ask that nobody ventures into the sea themselves on New Years Day as there won’t be the Usual First Responder presence on the beach.
"Thanks for all your support and We hope it may be possible to hold a similar event in the future, in that case hopefully see you on the beach 1st Jan 2022."
Visit their Facebook to donate to the RNLI if you wish.
Saundersfoot
Another cancellation, this time the popular New Year's Day Swim at Saundersfoot.
Organisers say they pride themselves on being able to keep the event safe, but this year it would be impossible to guarantee social distancing.
The 36-year-old event has raised more than £50,000 at each event in the past two years.
Follow their website for updates.
Find out more about events in your area here:
Porthdinllaen
The RNLI swim usually takes place on New Year's Day - but this year they are going virtual!
They are asking people to wear fancy dress (there'll be a prize) dip in some cold water at home and post the video to their Facebook page.
Those taking part are asked for a donation of £5 towards the RNLI. More details here.
