Swimming in the Rain: Is It Safe or Dangerous? (Solved!)

Once you’ve taken the liberty of swimming multiple times outdoors, you’re bound to run into a sudden downpour. If it’s your first time swimming in the rain, you have mixed thoughts about it. Should you continue swimming? Should you fear your safety?

Swimming in the rain can be unsafe because of the following hazards:

  • cool rain droplets promote hypothermia
  • higher risk of lightning in the area
  • greater likelihood of falling due to slick surfaces
  • resulting run-off carries pollutants into swimming reservoirs
  • heavy rains bring heavy winds, creating airborne projectiles

We will discuss all of these potential perils to a greater extent in the subsequent sections. Afterward, we’ll go over exactly how to handle the onset of rain if you’re in the middle of swimming. Make sure you read until the end to discover more information about whether or not it’s safe to swim again once a rainstorm has passed.

Why Swimming During Heavy Rain Isn’t Recommended

In the article’s opening, we briefly summarized the various reasons why swimming in the rain isn’t advocated. Although that bulleted list provided a short, concise answer to the question, it fails to encapsulate the whole picture.

Below, we’ll expand upon each of these points so that you can come away from this article with a better understanding of how each of these hazards negatively affects swimmers.

Cool Rain Droplets Promotes Hypothermia

Although it’s typically overlooked, a major risk that accompanies heavy rains is an increased risk of hypothermia.

As a quick reference, hypothermia is a condition where a person’s body temperature drops to precariously low levels, resulting in organ failure (source). Typically, the organs shut down when core body temperature has sunk below 95℉ (35°C).

Hypothermia is a direct consequence of sustained exposure to cold temperatures, as internal heat is slowly drained from the body. Over time, the effects of this heat loss compound until normal bodily functions abruptly cease.

Since precipitation lingers at high altitudes where the air is frigid, the rain droplets are also cold by default. When these rain droplets begin their descent towards the ground, they aren’t afforded nearly enough time to heat up, which is why rain feels cool to the touch.

Swimmers may be bombarded with a flurry of cool rain droplets during heavy rains. Prolonged exposure to these cool rain droplets gradually depletes internal heat from the body, giving rise to hypothermic symptoms.

You would think that a swimmer would be able to detect the onset of hypothermia easily. But, unfortunately, this is not the case.

The problem is that many swimmers confuse these hypothermic symptoms with the sudden shock of cold that runs through the body when immersing themselves in chilled water. This confusion allows the hypothermia to go untreated until their condition reaches a point where they can no longer ignore it.

The risk of organ shutdown is not something that you should deal with lightly. It’s no wonder why swimmers are advised to avoid swimming in rainy conditions to eliminate the threat of hypothermia.

Higher Risk of Lightning in the Area

In addition, heavy rainstorms also carry the threat of potential lightning strikes.

The most dangerous element of lightning is its unpredictable behavior. No one can pinpoint with certainty when and where lightning will strike next. Lightning will typically strike within a 10-mile radius of its parent thunderstorm, with an emphasis on the word typically. In the past, lightning has been reported to strike as far away as 50 miles from its parent thunderstorm (source).

50 miles! That’s quite the distance to keep track of as a swimmer.

The only hint that we are given as swimmers is that rain typically precedes lightning in most cases—and even that’s not a hard and fast rule. For this reason, it’s generally advised to stop swimming when heavy rains ensue, or thunderstorms are looming on the horizon.

However, if you’re intent on swimming in the rain, know that lightning can pose a problem. To give you some perspective, recreational pools must be closed and evacuated if a lightning strike has been identified within six miles of their present location (source).

So, if you witness nearby lightning, exit the water and get to shelter immediately. In this scenario, you definitely don’t want to risk getting back to land too late, as lightning can contact large bodies of water. Since water conducts electricity, being caught in the wrong place at the wrong time could have lethal consequences.

Greater Likelihood of Falling Due to Slick Surfaces

In addition, you must consider the fact that the rain makes ground surfaces slick, particularly when dealing with outdoor pool decks. This makes taking an accidental tumble far more likely, which can be extremely dangerous right next to the water.

If you fall and injure yourself on land, that’s one problem. However, an even worse scenario would be if you were to slip and incapacitate yourself, toppling over into the water. Under these circumstances, drowning is a real possibility, even if you consider yourself a fairly capable swimmer.

The sad truth is that drowning deaths do happen. In fact, according to the World Health Organization (WHO), drowning accounts for the third-most unintentional injury deaths globally, with 320,000 fatalities per year (source).

Since the risk of incapacitating oneself and drowning is significantly higher in the presence of slippery surfaces, this is yet another reason why swimming in rainy conditions is an ill-advised practice. Put simply, be especially careful with your footing when around bodies of water, regardless of whether the ground is wet or dry.

Resulting Runoff Carries Pollutants into Swimming Reservoirs

Furthermore, the runoff that collects on the ground and eventually tracks into bodies of water where people swim can bring contaminants along with it. When swimmers expose themselves to these contaminants for a sustained period of time, their health pays the price.

Examples of contaminants that storm runoff typically brings along with it include the following:

  • algae spores
  • dirt
  • dust
  • leaves
  • mulch
  • pollen
  • sewage

If you notice, many of these so-called contaminants have organic elements to them. Organic contaminants carry high levels of phosphate and nitrate, which can disrupt the careful chemical balance of pools.

Under normal circumstances, algae spores that find their way into these pools are typically killed off by the high concentration of chlorine and the lack of nutrients.

However, this high chlorine concentration is diluted during heavy rains, and much-needed nutrients—namely phosphate and nitrate—are made available to algae. This surge in algae growth can appear in as quickly as a day and even slightly shorter than that (source).

Needless to say, if such contaminants are not addressed early, swimmers will inevitably come into contact with this algal growth and risk contracting skin infections (source). These skin infections are certainly not worth a brief swim in the pool.

One can argue that contamination is even worse in open waters—such as oceans, lakes, and rivers—than in swimming pools. The main differentiating factor is that rain runoff can reroute large amounts of human garbage and sewage to open waters where people swim. Fortunately, this is not a problem with swimming pools.

Open water that grows noticeably murkier during rain showers can conceal many bacteria, parasites, and viruses. These are definitely something you want to avoid, as these are known to be disease-causing agents.

For example, a study was conducted to address whether or not there was any correlation between gastroenteritis and polluted water. After gathering and analyzing the data, there was an undeniable trend showing that as water quality decreased, the risk of gastroenteritis increased.

The study concluded that “swimming in even marginally polluted marine bathing water is a significant route of transmission for the observed gastroenteritis.”


In summary, pollution of swimming waters is yet another contributor to why it isn’t recommended that people swim in the rain, as the risk for illness outweighs any potential benefits that swimming may bring.

Heavy Rains Bring Heavy Winds, Producing Airborne Projectiles

The last health risk to consider is the danger posed by the heavy winds typical of rainstorms. As a rainstorm causes air pressure to fluctuate, these winds tend to pick up in heavy gusts. Occasionally, these heavy wind gusts have enough power to launch objects into the air and cause mass disarray.

If you’ve ever been to a pool during a rainstorm, you know exactly what I’m talking about. Seemingly all of the poolside furniture and accessories get tossed about. The gusts may first fling smaller items, such as clothes and towels, and eventually work their way up to larger items, such as poolside lounge chairs and umbrellas.

The unfortunate thing about this predicament is that many pool-goers become so attached to gathering their own personal belongings that they forget about their surroundings. This tunnel vision can have serious repercussions, as all it takes is one airborne projection to catch them off guard for injury to result.

This problem isn’t exclusive to pools either. This phenomenon can occur on the shores of oceans, lakes, and rivers as well.

To avoid such complications, attending lifeguards try to take early action and evacuate swimmers before these heavy winds even have a chance to wreak havoc. Sometimes, this early action simply turns out to be unnecessary, but other times it puts everyone out of harm’s way.

At the end of the day, it’s better to be safe than sorry. It would be best if you got back to land at the first sign of heavy precipitation so you can avoid dealing with such issues.

Is It Safe to Swim in Light to Moderate Rain Conditions?

You know the dangers that come with heavy rains, but what about light rain conditions?

The short answer is that the health risks that were just discussed still apply in light rain conditions, but to a lesser degree. For this reason, you should still look to swim in more cooperative weather whenever possible, as this is the safest way to avoid any health complications.

Nonetheless, if you’re intent on swimming despite a drizzle, be sure to proceed with the same level of caution. A light downpour that lasts only a few minutes shouldn’t be of any major concern, as this kind of rainfall is not usually severe enough to cause any critical damage to the body.

What to Do If It Starts Raining While You’re Swimming

With all these health risks in the back of your mind, you may be wondering how to handle a situation where heavy rain starts pouring while you’re still in the water.

Fear not; a step-by-step guide outlining exactly what to do in this scenario has been provided for you in the sections below. Becoming intimately familiar with these steps will afford you the confidence needed to maintain a level of calm and avoid succumbing to any rising feelings of panic.

Look for Signals from the Lifeguards

First off, you should look to the lifeguards on duty for guidance when a heavy downpour kicks in. They may begin relaying signals or blowing their whistles to let people know that the conditions are currently unfit to swim.

If they aren’t showing any signs of shutting down the pool or beach, you may want to confer with the lifeguard staff on your own to see what their thoughts are on the matter.

Often, they’re simply waiting to see if the rainstorm is on the verge of passing by or growing worse. Whatever the trend may be, they’ll be better equipped to make a judgment call when this time for observation is up.

Evacuate the Water Immediately

When heavy rainfall continues for several minutes with no signs of letting up, it’s time to get back on land. This way, you won’t have to deal with the brunt of the rainstorm when it comes. You put yourself at much greater risk when you refuse to exit the water before the peak of the downpour.

There may be other times where you exit the water, and the rain ceases shortly afterward. Although it may be somewhat tedious, it’s better to be safe than sorry.

Find Shelter & Wait Out the Rainstorm

If it’s still raining hard once you get back on land, get somewhere indoors as quickly as you can. Not only will you be dry, but you’ll also be out of harm’s way for a potential lightning strike.

As you know, rain often precedes lightning during thunderstorms. Given how unpredictable lightning strikes can be, you want to find shelter promptly, regardless of how low the chances of being in the vicinity of lightning may seem.

Is It Safe to Swim Again Once the Rain Stops?

Once a rainstorm has passed, many swimmers are under the impression that it is safe to resume normal activities, almost as if there was no precipitation in the first place.

Not so fast.

Just because the rain stopped doesn’t mean that its health risks have gone with it. Oftentimes, there may still be lingering dangers that can pose a threat to swimmers.

For example, even when precipitation has ceased, the threat of lightning may persist if the parent thunderstorm is still within close vicinity of the swimming area.

To prevent swimmers from hopping back into the water too quickly, lifeguards have been instructed to wait a minimum of 30 minutes after visible lightning before re-opening a swimming area. There must be no recurring instances of lightning; otherwise, the 30-minute count will have to reset (source).

Moreover, ground surfaces may still be slick following a rainy downpour, so swimmers should take extra precautions if they choose to re-enter the pool.

Lastly, any pollutants that found their way into the swimming area during a rainstorm must be cleared out before people can re-enter the water. For pools, this may mean bringing out a skimmer net to remove debris—like leaves and twigs—from the water.

Oceans, lakes, and rivers are a different matter entirely since sewage may be involved. If the water looks noticeably discolored, it’s likely not a smart idea to resume swimming for the day. It may take anywhere from 12 to 72 hours for this pollution to clear away, with 72 hours being the safest bet for safe swimming activity (source).

Put simply, it really depends on the particular circumstances of the rainstorm. If lightning is involved, you should wait 30 minutes at the very least. If water discoloration is involved, it’s in your best interest to leave these open waters alone and look elsewhere—or simply come back another day.

Final Words

Swimmers should get out of the water during a heavy downpour, as the experience of swimming under these conditions is not worth the risk of potential health complications.

Although swimming in a drizzle is generally acceptable, you still may want to consider waiting out the rainstorm on land for safety. With all that being said, don’t let the prospect of rain deter you from venturing out to the water. Good luck!

All content written by HydroPursuit is for informational purposes only. The material found on this site is not intended to replace professional medical advice, treatment, or diagnosis. Consult with an accredited health care provider prior to initiating a new health care regimen.

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Austin Carmody

I am the owner of HydroPursuit. I enjoy kicking back and getting out on the water as much as I can in my free time.

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