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A guide to understanding wind and rain


The wind and rain are no strangers to cold water swimmers. The wind and rainfall can be a nuisance, but they can also provide an atmospheric experience whilst swimming.

We get to experience these elements uniquely, watching the water droplets bounce off of the water as a gust of wind helps us along in our cold water swim.

However, the wind and rain can pose potential risks in the UK. We must understand wind and rain to stay safe while swimming in open waters.

Read our guide to understanding wind and rain now!

Potential dangers of wind and rain

At Cold Water Swim, we have researched the potential risks of swimming during high winds and heavy precipitation. Understanding wind and rain is critical.

Wind and rain can drastically alter the conditions of your local land and waterscapes, making them more dangerous in the waters.

We hope that by giving our community an understanding of the risks and effects of dangerous weather, they can assess potentially treacherous conditions and remain vigilant.

1. Underwater currents

Heavy rainfall can lead to strong currents. Therefore, swimmers must take extra care. Strong currents can cause swimmers to be dragged past exit points and into debris which could lead to bad injuries or worse.

Even though flying down fast rivers can be fun, it’s important that strong currents are treated with reverence. So, take note of any ripples on the water’s surface or water travelling against the wind direction.

Riptides are strong underwater currents found in oceans close to the shore. If you find yourself stuck in a riptide, you should swim parallel to the shore to escape.

Always wear a tow float when swimming in windy or rainy weather, as this will help you stay visible should you get into any difficulty or need rescuing.

2. Turbulent waters

Turbulent and white water travel much faster than usual; they often occur near waterfalls, pools and weirs. White waters should be avoided, especially after heavy rain or extreme weather, as this can ramp up their strength.

Turbulent waters can easily pull parts of riverbanks away, so it’s clear why we don’t recommend going for a swim in them! You can get dragged below the surface, making swimming much more difficult.

Swimming in rapid waters can be extremely tiring, so a buoyant wetsuit and tow float are always recommended if you want to go for a dip. However, we would advise avoiding swimming in white waters altogether.

white water

3. Hidden debris

Thunderstorms and typhoons bring strong wind and heavy rain, causing water levels to rise, which could lead to a storm surge.

Storm surges caused by low-pressure weather systems increase sea levels and wind speed, forcing water towards coastlines.

Huge surges of water from storms can bring hidden debris, anything from a street sign, logs, and branches to a large chunk of sediment.

Always assess the area you wish to swim in before entering the water, particularly if there have been strong winds or storms. If you cannot see into the water, take extra care getting in, use an underwater camera, or find another, safer location.

4. River levels and flooding

Heavy rain can cause river banks to burst and flood causing drastic changes in the land and waterscape.

Flooding, landfall and rising water level can block any known entry or exit points you’re familiar with, making your usual swim routes unsafe.

You must always scout entry and exit points before swimming, especially after bad weather.

river flood

5. Tidal rivers

Tidal rivers are especially dangerous during thunderstorms, and the tide can push back against the river’s natural flow.

Meaning that hidden debris and pollution could be coming from either direction, as well as dangerous currents.

Understanding wind and rain is important for your safety. When swimming in tidal rivers, it’s always best practice to check the tidal times and weather chart to ensure the safest times to swim.

6. Harsh winds

Strong winds don’t mean you need to call off your swim. However, it’s important to consider the most suitable location when swimming in high winds.

The stronger the winds, the more you need to take care. Falling debris and strong waves are dangerous to swimmers, so you must assess your surroundings before taking the plunge.

Understanding wind and rain is easy with the right tools. Check the wind speed (typically in mph) on weather apps and check the movement of air at your swimming location.

If the wind is sweeping debris into the water or changing the direction of the water, it is best to save swimming for another day.

7. Cold 

Cold fronts bring sudden drops in water and wind temperatures, which can greatly impact us whilst wild water swimming. Luckily, wetsuits insulate swimmers and help retain their body heat.

Dry suits also stop the cold water from touching your skin, preventing you from getting too cold out of the water or even, in extreme cases stopping hyperthermia.

You don’t need clear skies and warm air to swim. Our favourite months to swim include those amid autumn and winter. However, extra precautions must be taken to ensure your safety in the icy conditions.

8. Pollution

Rivers, lakes, and oceans can all be affected by pollution after heavy rainfall. Harmful agricultural run-off, sewage, and litter are just a few examples of what can be washed into our swimming waters.

The Rivers Trust has mapped all sewage run-offs, so you can check if your local river is safe to swim in. Using local knowledge or maps is useful to see if you’re swimming near anywhere that could bring pollution.

Pollution has a direct influence on global warming, so we cold water swimmers must care for the environment we enjoy. If we do a little bit, we can prevent rising atmospheric pressure, sea levels, and temperatures.

river pollution


Can you swim in open water after heavy rain?

After heavy rain, you should check for any burst banks or blocked exit points on your swimming route to ensure its safety. You must keep an eye out for debris in the water after a rainstorm that could obstruct you as you swim.

Strong winds and thunder can also follow heavy rain. So, we recommended keeping an eye on the weather map before heading out.

If you ever feel ill or sick after a swim, especially after heavy rain, you must seek medical advice. The water could be polluted, so better to be safe and consult a doctor.

How to be weather aware

Before going cold water swimming, it’s best practice to check the weather conditions and act accordingly.

If the weather says it could rain, it’s important to remember that rain could also bring strong winds, thunder, lighting, choppy waves, currents, etc.

However, if it looks like just a light shower, you’re more than fine to swim! Being weather aware is all about taking your situation’s context and using that to help inform your decisions.

Here are some top tips:

  • Different locations will face various risks with wind and rain. For example, the Atlantic and Indian Oceans will pose more of a threat in rough conditions than a sheltered lagoon will due to tides and exposure.
  • Fun fact – the Coriolis Effect makes storms in the Northern Hemisphere swirl counterclockwise and showers in the Southern Hemisphere swirl clockwise. Depending on the direction of the wind and your location near the equator, you can take precautions when there are storm warnings nearby.
  • Take note of the weather forecast and use common sense when deciding whether the conditions at your location are safe enough for swimming.

What equipment will help keep you safe from the wind and rain?

Equipment, such as tow floats and changing robes, can help keep you safe from the wind and rain.

Dry bags are an excellent and convenient investment for cold water swimmers to stash their belongings to keep them dry.

Changing dry robes are the best for when you need to change in the rain; you can get changed underneath them whilst keeping all your clothes dry before and after a swim! Check out our favourite dry robes!


Mother nature can sometimes throw a spanner in the works regarding our cold water swimming plans! Turbulent waters, hidden debris, pollution, and flooding are all real risks to us after heavy rain and wind.

With the help of our article, you can understand the wind and rain. You can identify the dangers and assess your surroundings appropriately to decide whether to take the plunge!

So, understanding wind and rain isn’t that hard! Right? Check the weather forecast, take sensible equipment, swim with a friend, and don’t be scared to wait for a sunnier day.