How Long Should You Swim in Cold Water?
Updated January 2026
When swimming outside in the UK you are going to experience much colder temperatures than swimming in an indoor swimming pool. Outdoor waters in the UK can be as cold as zero degrees in the winter and around 20 in the summer, so it’s important to know before you expose yourself to these temperatures how long you should swim in cold water.
You may be thinking, is cold water swimming good for you? Cold water swimming comes with many benefits. Exposing your body to cold water for too long, and without the proper precautions, can lead to your body losing heat, muscles losing power, and limbs becoming heavy and slow leading to a risk of drowning.
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What is cold water shock?
Cold water shock is your body’s response to the sudden drop in temperature when you immerse yourself in cold water. The sudden drop in skin temperature can cause high blood pressure, a sharp intake of breath and an increased breathing rate. Cold water shock usually only lasts a couple of minutes before your body adjusts to the new temperature, but to the inexperienced, it can be a scary and sometimes deadly response.
To help you mitigate cold water shock, enter the water slowly to give your body time to adjust and mentally prepare yourself for the temperature change!
Cold Water Swimming Guidelines
If you are looking to swim in cold water for a long period of time then we would recommend swimming nearer to the shore so you can easily get out before your body begins to struggle from the effects of cold water shock.
Swimming in cold water is perfectly safe for most people, as long as you take a few precautions. First, it’s important to acclimatise yourself to cold water gradually. Start by swimming for short periods of time, and gradually increase your endurance as your body gets used to the colder temperature.
Second, be sure to wear appropriate clothing. A wetsuit or dry suit will help to trap your body heat and prevent hypothermia. By following these simple guidelines, you can enjoy cold water swimming without any risks.
We also have a handy article on cold water swimming safety tips.
What temperature is cold water swimming?
Roughly speaking, cold water temperature should be under 18 degrees for swimming to be considered cold water swimming. Let’s look into the different cold water temperatures and how to swim in them safely:
Cold Water Temperature Guide
0 to 10 Degrees
These water temperatures are suitable for extreme cold water swimmers throughout the winter months when the temperature drops. Unless supervised, you should only be swimming in 10-degree water for a few minutes and should wear a wetsuit unless you are an experienced cold-water swimmer.
10 to 15 Degrees
Lakes and seas start to reach these temperatures in the spring in the UK, as it begins to get warmer. The water still is extremely cold and can still have negative effects on your body if you are exposed for a long period of time.
At these temperatures, hyperthermia and increased blood pressure can be a risk, although most healthy adults are likely to be fine – making this the ideal cold water swimming temperature. Experienced swimmers can manage this temperature for several hours.
15 to 25 Degrees
15 to 25 degrees is a comfortable swimming temperature and is around the temperature that most swimmers find comfortable with. There might be an initial feeling of cold when you enter the water, but you should acclimatise and be comfortable with this temperature, and be able to stay in the water for several hours at a time at no risk.
25 to 30 Degrees
Between 25 to 30 degrees, these temperatures can be too high for people to swim for long periods of time and can be a risk. We would recommend staying hydrated and swimming for short periods of time to avoid heat stroke.
How long can you swim in cold water when pregnant?
Your body’s temperature regulation isn’t as good when you’re pregnant, so if you do decide to take a dip in cold water, do bear this in mind. It is recommended to only swim in cold water for 1 – 2 minutes when pregnant, but listen to your body and if you feel comfortable you can swim a little longer.
Just ensure you have everything ready to warm back up when you get out!
Open Water Swimming Lake at Bicester Gym
As mentioned, there are many benefits of cold water swimming such as reducing inflammation, improving cardiovascular health and increasing endurance. Yet it’s important to be aware of the risks and the temperatures before exposing yourself to open water.
To help you reap the benefits of cold water swimming and start a new hobby, we offer an outdoor swimming lake with a 200m body of water, perfect for advanced or amateur swimmers.
Our open-water swimming lake in Oxfordshire is the perfect place to host your outdoor team-building activities or fitness classes. Whether you are looking to improve your swimming skills, or to simply get fitter, we offer swimming lessons at different levels. Lessons start from the very beginning to help you achieve and develop a fantastic new skill.
To find out more information about our 200m outdoor swimming lake, then please get in touch today!
