Is It Safe To Swim In 100 Degree Weather?

Marjan Sokolovski

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As the mercury rises and summer’s scorching embrace tightens its grip, the allure of a refreshing swim becomes irresistible. But as the thermometer climbs towards triple digits, a vital question arises: Is it safe to swim in 100-degree weather? 

While swimming can provide a delightful escape from the heat, it’s crucial to navigate the fine line between enjoyment and potential danger. In this blog post, we’ll delve into the considerations and precautions necessary when contemplating a dip in extreme heat. 

We’ll explore the effects of soaring temperatures on the body, discuss the importance of hydration and sun protection, and offer guidance on when it might be best to postpone that pool or beach day. 

The risks and knowing how to mitigate them ensures that your summer swims remain both enjoyable and safe. Stay focused. 

When Is It Too Hot to Swim Outside?

The ideal outdoor swimming temperature varies depending on personal preferences and individual tolerance to heat. 

However, there are general guidelines to determine when it might be too hot to swim outside safely.

High Temperatures

When the air temperature rises significantly above 90°F (32°C), it can become uncomfortable and potentially dangerous to swim outdoors. 

Swimming in hot weather can lead to heat-related illnesses like heat exhaustion or heatstroke.

Sun Exposure

Intense sunlight combined with high temperatures can increase the risk of sunburn and skin damage, making it less enjoyable to swim.

Water Temperature

While warm water can be pleasant, if the water temperature exceeds 90°F (32°C), it might not provide relief from the heat, and swimmers can feel overheated.


High humidity levels can make hot weather feel even more oppressive, affecting your comfort and safety while swimming.

The decision to swim outdoors in hot weather should consider individual health and comfort.

What Is the Appropriate Temperature For Swimming?

The appropriate temperature for swimming can vary depending on individual preferences and the type of swimming activity. Here are some general temperature guidelines:

Indoor Pools

Indoor pools are typically maintained at a temperature range of 78°F to 82°F (25°C to 28°C). 

This range provides a comfortable environment for various swimming activities, including lap swimming, water aerobics, and recreational swimming.

Outdoor Pools

The ideal outdoor pool temperature often falls between 78°F and 84°F (25°C to 29°C). This range accommodates a wide range of swimmers and activities while avoiding water that’s too cold or too warm.

Open Water Swimming

For open water swimming in natural bodies of water (such as lakes, rivers, or oceans), the ideal water temperature can be somewhat subjective. 

Many open-water swimmers prefer water temperatures between 60°F and 70°F (15°C to 21°C). Water that is too cold can be uncomfortable and pose safety risks, while water that is too warm can lead to overheating.

Hot Tubs

Hot tubs are typically heated to a higher temperature range, around 100°F to 104°F (37°C to 40°C), for relaxation and therapeutic purposes.

It’s important to note that individual preferences and tolerance to temperature can vary widely. 

Some people may prefer slightly cooler or warmer water, so it’s essential to pay attention to your own comfort and safety when swimming in hot weather. 

Additionally, children and older adults may have different temperature preferences and needs, so it’s a good idea to consider the preferences of all swimmers when choosing a water temperature for a group activity.

Is It Safe To Swim In 100 Degree Weather?

Now, you must be thinking about whether is it safe to swim in 100-degree weather. 

Swimming in 100-degree weather can be safe, but it requires careful consideration of several factors to ensure your safety and well-being. 

Here are some important considerations:


Extremely hot weather can lead to dehydration, especially when combined with physical activity like swimming. 

It’s crucial to stay well-hydrated by drinking plenty of water before, during, and after swimming in hot weather. Dehydration can lead to heat-related illnesses, so pay close attention to your fluid intake.

Sun Protection

In hot weather, the sun’s UV rays can be intense. Protect your skin from sunburn by wearing sunscreen, a wide-brimmed hat, and sunglasses. 

Consider swimming in shaded areas or during times of the day when the sun is less intense, such as early morning or late afternoon.

Heat-Related Illnesses

Swimming in hot weather can increase the risk of heat-related illnesses, such as heat exhaustion or heatstroke. Be aware of the signs and symptoms, which may include dizziness, nausea, rapid heartbeat, and confusion. 

If you or anyone in your group experiences these symptoms, get out of the water, rest in a cooler place, and seek medical attention if necessary.

Water Temperature

While air temperatures may be hot, it’s essential to consider the water temperature as well. 

If the water is excessively warm, it may not provide the desired relief from the heat. Water that is too warm can also increase the risk of overheating while swimming.

Swimming Ability

Ensure that all swimmers are skilled and confident in the water, especially in hot weather. High temperatures can lead to fatigue more quickly, so it’s essential to have the necessary swimming skills to stay safe.


If you’re swimming with children or inexperienced swimmers, provide close supervision to ensure their safety. 

Children, in particular, may not recognize the signs of heat-related issues, so it’s important to watch for any signs of distress.

So swimming in 100-degree weather can be safe with proper precautions. Stay hydrated, protect yourself from the sun, be aware of the signs of heat-related illnesses, and consider the water temperature. 

Always prioritize safety when swimming in extreme weather conditions.

Swimming During Heat Advisory

Swimming during heat advisory requires special attention to safety due to the extreme heat conditions. 

A heat advisory is typically issued by meteorological authorities when the combination of high temperatures and high humidity can pose health risks. 

Here are some important considerations for swimming during heat advisory:

Stay Informed 

Before heading out to swim, check the local weather forecast and any heat advisories issued for your area. Pay attention to heat index values, which factor in both temperature and humidity to determine how hot it feels.

Choose the Right Time

Consider swimming during cooler parts of the day, such as early morning or late evening when the sun is less intense and temperatures are slightly lower. 

Avoid swimming during the hottest part of the day, typically between 10 a.m. and 4 p.m.


Prioritize hydration. Drink plenty of water before, during, and after swimming. Avoid alcohol and caffeine, which can contribute to dehydration. Dehydration can increase the risk of heat-related illnesses.

Sun Protection

Protect yourself from the sun’s harmful UV rays by wearing sunscreen, sunglasses, and a wide-brimmed hat. Seek out shaded areas when not in the water to reduce sun exposure.

Swim in Safe Conditions

Ensure that the swimming area is well-maintained and supervised, especially if you’re swimming in a public pool or at a beach. Pay attention to any safety warnings or advisories related to water quality or currents.

Know Your Limits

In extreme heat, physical activity can lead to faster fatigue and potential heat-related problems. 

Be aware of your physical condition and listen to your body. If you start to feel dizzy, nauseous, or overly fatigued, get out of the water and rest in a cooler area.

Swimming Partners

It’s safer to swim with a buddy during a heat advisory. In case of any emergencies or health issues, having someone with you can be crucial.

Children and Vulnerable Individuals

Be extra cautious with children, the elderly, and individuals with pre-existing health conditions, as they may be more susceptible to heat-related illnesses.

Emergency Preparedness

Familiarize yourself with the location of nearby emergency services and know how to contact them in case of an emergency.

Follow Official Guidance

If local authorities advise against outdoor activities, including swimming, during a heat advisory, it’s best to heed their advice for your safety.

Swimming during heat advisory can be enjoyable if you take the necessary precautions.

Is It Safe To Swim in Excessive Heat?

If you don’t know whether is it safe to swim in extreme heat, you should first learn how hot is too hot to swim. Swimming in hot weather can be enjoyable, but it also poses unique challenges and risks. 

Here are some elaborate points to consider regarding the safety of swimming in excessive heat:

Heat-Related Illnesses

Excessive heat, especially in combination with high humidity, can increase the risk of heat-related illnesses such as heat exhaustion and heatstroke. These conditions can be life-threatening if not addressed promptly. 

Signs of heat exhaustion include heavy sweating, weakness, dizziness, and nausea, while heatstroke can lead to a rapid pulse, confusion, and loss of consciousness. Swimming while experiencing these symptoms is dangerous.

Hydration is Critical

Staying well-hydrated is paramount when swimming in excessive heat. The combination of physical exertion and high temperatures can lead to rapid fluid loss through sweat, which can increase the risk of dehydration. 

Drink plenty of water before, during, and after swimming to maintain proper hydration levels. Avoid alcohol and caffeine, as they can contribute to dehydration.

Time of Day Matters

Choose the time of day for swimming wisely. Excessive heat is typically most intense between 10 a.m. and 4 p.m. Consider swimming during the cooler hours of early morning or late evening to reduce the risk of heat-related issues. 

The sun’s intensity is also lower during these times, reducing the risk of sunburn.

Sun Protection

The sun’s ultraviolet (UV) rays can be particularly strong during hot weather. 

Protect your skin by wearing sunscreen with a high SPF rating, sunglasses, and a wide-brimmed hat. 

Reapply sunscreen regularly, especially if you’re in and out of the water.

Swimming Environment

Be aware of the specific swimming environment. Ensure that swimming areas are well-maintained and safe, especially if swimming in open water or public pools. 

Follow any posted rules or advisories regarding water quality, currents, and safety guidelines.

Physical Limitations

Excessive heat can lead to quicker exhaustion during physical activity, including swimming. 

Know your physical limitations and don’t push yourself too hard. Pay attention to signs of fatigue, dizziness, or discomfort, and take breaks when needed.

Supervision and Companionship

It’s safer to swim with a companion, especially during excessive heat, in case of an emergency or health issue. 

If you’re swimming with children or individuals who may be vulnerable to heat-related problems (such as pre-existing health conditions), provide close supervision and ensure they are also protected from the heat.

Swimming in excessive heat can be safe if you take precautions and remain vigilant about your health and safety.


Is it safe to swim in 105-degree weather?

Swimming in 105-degree weather can be risky. Such extreme heat can lead to dehydration, heat exhaustion, and heatstroke. 

It’s crucial to stay hydrated, avoid prolonged sun exposure, and swim during cooler parts of the day to reduce the risk of heat-related illnesses.

Is it safe to swim in 110-degree weather?

Swimming in 110-degree weather is not advisable. The heat poses a significant risk of heat-related illnesses, and the water may not provide sufficient relief. 

It’s safer to avoid swimming in these conditions and opt for indoor pools or cooler times of the day.

When is it too hot to swim?

Swimming can become unsafe when the combined factors of high temperature and humidity increase the risk of heat-related issues. 

Generally, temperatures above 90°F (32°C) or during heat advisories warrant caution. Staying hydrated, using sun protection, and knowing your limits are crucial in hot weather.

What precautions should I take when swimming in very hot weather?

When swimming in very hot weather, prioritize hydration, wear sunscreen and protective gear, choose cooler times of the day, and be aware of heat-related symptoms like dizziness and nausea. 

Always supervise children and be cautious with vulnerable individuals, such as the elderly or those with health conditions.

Can children safely swim in 100-degree weather?

Children can swim in 100-degree weather, but it requires careful supervision, hydration, and sun protection. 

They may be more susceptible to heat-related problems, so ensure they take frequent breaks, drink water, and stay shaded when not in the water. Always prioritize their safety in extreme heat.

Wrapping Up

In summertime, the allure of swimming is undeniable, even when faced with sweltering 100-degree weather. 

However, safety must always be paramount. This blog post has explored the various aspects of swimming in extreme heat, from recognizing the potential risks to implementing essential precautions.

While swimming can provide respite from the heat, it’s essential to exercise caution, prioritize hydration, and protect yourself from the sun’s rays. 

Knowing your limits and understanding when it might be too hot to swim is key to enjoying this summer activity without compromising your well-being. 

So, whether you choose to dive in or bask poolside, do so with the knowledge and awareness necessary to keep your summer swimming adventures safe and enjoyable. Best wishes. 

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Marjan Sokolovski

I am a professional swimming coach who has been coaching for over 20 years. I have coached athletes in the Olympics and Paralympics, and I have also helped to train people across the world. I started my coaching career by teaching swimming lessons at a local pool. I was really passionate about teaching people how to swim, but I quickly realized that this wasn't enough for me. I wanted to make a difference in people's lives and help them achieve their goals. I started working with athletes in high school, college, and then professionally. The best part about coaching is that you get the opportunity to work with so many different types of people from all walks of life - it's just incredible! LinkedIn

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