Is it Safe to Go Swimming in the Ocean After it Rains?

After a bout of rainfall, the skies clear up and the sun emerges, and you are probably raring to take a dip into the ocean once again. And while you may know that it’s unsafe to swim in the ocean while it’s raining, you might not know that the danger isn’t over just because the rain stopped.

swimming in ocean after rain

The primary concern after rainfall isn’t the rain itself but the aftermath it leaves in the ocean waters. Rain can introduce a slew of pollutants, bacteria, and altered ocean conditions that might make your next swim less than pleasant—and, in some cases, hazardous. You should wait 48-72 hours before swimming in the ocean after rainfall.

Keep reading on as we go over the exact reasons why it’s not a good idea to swim in the ocean so soon after it rains.

Risks of Swimming in the Ocean After Rainfall

Polluted Runoff

Rain acts like nature’s broom, sweeping away everything in its path on roads, sidewalks, and lands. As it washes over these surfaces, it collects pollutants like pesticides used in gardens, oil spills from vehicles, and other chemicals from industries. When these get washed into the ocean, the water becomes contaminated. 

This contamination is termed “runoff pollution”. For swimmers, entering such water means exposing their skin and body to these harmful pollutants. Over time or due to intense exposure, these chemicals can lead to skin problems, allergic reactions, or even systemic health issues if they are ingested.

Bacterial Contamination

When it rains, water doesn’t just wash away inorganic pollutants; it also transports organic materials, such as animal waste, sewage overflows, and decaying plant matter into the ocean. These organic substances can contain harmful bacteria, including pathogens like E. coli. 

For those unfamiliar with the term, a pathogen is a microorganism that can cause disease. So, when you swim in such contaminated water, you risk getting infections that can affect the skin, stomach, or even respiratory system.

Reduced Visibility

Rain has the ability to stir up sand, silt, and other tiny particles from the ocean floor. This process makes the clear ocean water turn cloudy or murky, reducing the visibility within. 

For a swimmer, this is similar to driving in heavy fog; it becomes hard to see what’s ahead. In the context of the ocean, this means swimmers might not notice hazards like submerged rocks, marine animals, or even other people in the water, leading to potential accidents or injuries.

Rip Currents

Ocean currents are like rivers within the ocean, streams of water flowing in a definite direction. Rain, especially heavy rain, can introduce a large volume of freshwater into the ocean, altering these currents and sometimes making them stronger. 

Among these, rip currents pose a notable threat. A rip current is a strong and narrow current that moves directly away from the shore, and it can quickly pull swimmers out to deeper waters. 

And do you think you can outswim a rip current? Many people, even experienced swimmers, have lost their lives trying to escape from a rip current’s grip, making it a significant drowning risk.

Storm Surges

Storms that bring heavy rainfall can also cause a phenomenon called a “storm surge”. Imagine the ocean as a large bathtub. When a storm approaches, it’s like someone pushing water towards one end of the tub, causing it to rise and overflow. 

That’s essentially a storm surge, where strong winds push seawater towards the shore, leading to sudden and temporary increases in sea level. This surge can create unpredictable and large waves, making swimming or even just being near the shore dangerous.

Debris in the Water

After a downpour, the ocean can look like a messy room with scattered toys. The “toys”, in this case, are debris such as trash, fallen tree branches, and other floating materials that the rain washed into the sea. 

Swimming in such conditions means navigating through this mess, and there’s always the risk of getting injured by sharp or large objects.

Water Quality Uncertainty

Think of water quality reports as a health report for the ocean. After it rains, this report might be outdated since the rain could have introduced new pollutants. Testing the water to get an updated “grade” can take time. Swimming immediately after rainfall means diving in without knowing the current state of the water’s health, making it a gamble for swimmers.

Altered Marine Behavior

The influx of freshwater and potential change in water conditions after rainfall might confuse or disturb marine life. Some species might move closer to shore due to these changes. 

For swimmers, this means a higher chance of unexpected encounters with marine animals, which could lead to bites, stings, or other negative interactions.

Jellyfish Blooms

Jellyfish can sometimes increase in numbers after rains, especially in certain regions. This increase, commonly known as a “bloom”, can pose risks to swimmers. Some jellyfish stings are not just painful but can also cause allergic reactions or other health complications.

Erosion and Altered Landscape

Lastly, rain can erode the shoreline, meaning it can wear away the sand and change the shape or features of a beach. This erosion can create new underwater hazards, like exposing previously hidden rocks. 

It might also change the ocean floor’s slope, affecting how waves break and creating new currents. For regular visitors, a familiar beach might suddenly become unfamiliar and potentially hazardous.

Frequently Asked Questions

When is it safe to swim in the ocean again after it rains?

Health experts recommend avoiding swimming in the ocean for at least 48 hours after it rains to reduce the risk of exposure. However, this may vary depending on the location, the amount of rain, the water quality, and the water circulation. You should check the local water quality reports and advisories before swimming in the ocean after it rains

How can I stay updated about water quality after it rains?

You can stay updated about water quality after it rains by checking the local water quality reports and advisories that are issued by public health authorities or environmental agencies. 

These reports and advisories provide information on the bacterial levels, contaminants, and safety of the ocean water for recreational activities such as swimming, surfing, or fishing. They also indicate how long the rain advisory is in effect and when it is safe to resume water activities. 

You can find these reports and advisories online, by phone, or by email depending on your location.

What precautions should be taken if one decides to swim after it rains?

Some precautions that should be taken if one decides to swim after rain are:

  • Check the local water quality reports and advisories before swimming and avoid swimming in areas that are known to be polluted or have high bacterial levels.
  • Avoid swimming in cloudy, murky, or discolored water as it may indicate the presence of contaminants or harmful organisms.
  • Avoid swimming near storm drains, pipes, outfalls, or areas where water runoff enters the ocean as they may carry pollutants from the land.
  • Avoid swimming if you have open wounds, cuts, or infections as they may increase the risk of exposure to bacteria or pathogens.
  • Avoid swallowing water or putting your head under water as it may increase the risk of ingesting contaminants or pathogens.
  • Shower with soap and water after swimming to remove any dirt or germs from your skin and hair.