Running in Humidity: 5 Essential Tips to Conquer the Heat

Running in humidity can be a challenge for all levels of runners, from newbies to seasoned athletes. In fact, exercising in humid weather can lead to dehydration and other heat-related illnesses.

But don’t worry—this blog post provides you with 5 essential tips to stay cool and comfortable when running during the hot and humid months. Discover how you can battle the humidity while staying in shape with our expert tips!

How Does Humidity Affect Running?

High humidity can make running difficult by hindering sweat evaporation and decreasing endurance. However, running in humidity has several potential benefits, such as improved cardiovascular fitness, lower resting heart rate, and better overall performance.

Humidity and Running: Characteristics of Humidity and How It Affects Running

Humidity is the amount of moisture in the air, which can be measured with a hygrometer and expressed as a percentage. When humidity levels are high, it means there’s more “stickiness” in the air due to all that extra water vapor present.

High humidity makes running particularly challenging, because it makes breathing feel more difficult and forces you to take in more moisture with each breath. It also causes your clothing to stick close to your body and causes you to sweat even faster than usual when exercising in hot climates.

Higher temperatures combined with high humidity can lead to increased fatigue, decreased performance, shallow or labored breathing, light-headedness, and exhaustion due to overheating.

The runner runs on a warm summer day

How the Body Reacts to Running in High Humidity

Humidity makes warm summer runs feel even hotter, as sweat evaporates more slowly from the body. This means that it is harder for our bodies to cool themselves down during a run and increases the risk of heat illnesses, such as heat exhaustion and heat stroke.

Breathing can also be more difficult in humid air for some people, as the air is thicker, making it harder to take deep breaths while exercising.

Running in Humidity – 3 Benefits

Running in humid climates can be challenging, but it also has several benefits:

1. Better Cardiovascular Fitness

When the air is more saturated with moisture, it impairs our ability to keep cool and increases the level of heat stress on our bodies during physical activity. This extra strain forces our hearts and lungs to work harder as they try to deliver enough oxygenated blood and remove waste products from the cells, increasing their strength and power over time.

Consequently, running in hot weather can enhance cardiovascular endurance by allowing us to better cope with high-intensity workouts in a challenging environment. This also results in increased calorie burn and improved cardiac health outcomes.

2. Lower Resting Heart Rate

Running in hot and humid conditions can improve a runner’s resting heart rate. Heat training has been found to decrease the average resting heart rate by up to 10 beats per minute when done consistently over time.

This result is achieved through the physiological effects of increased sweat loss, increased vagal nerve activity, improved blood plasma volume, and improved heat tolerance.

3. Enhanced Overall Performance

With the right knowledge and preparation, high humidity can become an effective training tool.

Running in humid conditions increases the sweat rate significantly, forcing the body to work harder to stay cool by increasing heart rate and blood pressure for proper thermoregulation. This leads to improved endurance and enhanced overall performance.

The runner takes effective training in high humidity

Dew Point Running Chart

Wondering how to determine your pace when running in 90% humidity? The most important thing to understand is that dew point, which is a measure of atmospheric moisture expressed as a temperature, directly affects running performance. By being aware of the dew point and using calculations or pre-set tables, runners can make decisions about their race pace to accommodate the level of humidity they are facing.

To calculate adjusted pace due to humidity levels, simply use the dew point running chart. This chart by Coach Mark Hadley explains the adjustment needed for speed and provides relative adjustments by distance.

Temp °F/
Dew point °F

The table shows the sum of temperature and dew point. You then adjust your pace by this parameter.

Temperature+Dew PointPace Adjustments
100 or lessNo adjustment
101- 1100% to 0.5% adjustment
111- 1200.5% to 1.0% adjustment
121-1301.0% to 2.0% adjustment
131-1402.0% to 3.0% adjustment
141-1503.0% to 4.5% adjustment
151-1604.5% to 6.0% adjustment
161 -1706.0% to 8.0% adjustment
171- 1808.0% to 10.0% adjustment
Above 180Intense running not recommended

For instance, if the dew point temperature is 65°F and the temperature is 85°F, giving you a sum of 150, then it’s recommended that runners adjust their pace by -3-4.5%. This means that if your usual pace is 8 min per mile, then you should change it to 8:14-8:22 per mile. Keep in mind that running in 100% humidity is generally unsafe.

Using this guideline to calculate necessary adjustments can make a significant difference in how successful you are at conquering a run on a hot day.

5 Tips for Running in Humidity

To perform at your best and conquer the heat, it is important to learn how to handle humidity. Read on to discover 5 essential tips for running in humid conditions.

1. Run by Effort, Not By Pace

One of the key strategies for running in humid weather is to focus on effort rather than pace. Excessive humidity and heat can greatly affect your performance, making it nearly impossible for you to run at your normal pace.

Your body requires more energy and oxygen, since it takes more effort to cool down. Therefore, instead of chasing an unrealistic goal, like setting a personal record during extreme weather conditions, shift your focus to how hard you’re working and adjust expectations accordingly.

2. Hydrate Before and During Your Run

It’s important to stay hydrated when running in humid weather, as high humidity levels can contribute to dehydration and put you at risk of heat-related illnesses. Dehydration magnifies the effects of fatigue, making it more difficult for your body to regulate its temperature and cope with exercise.

Hydrating and consuming electrolytes before and during a long run increases fluid reserves stored in the body. If they become depleted too quickly or aren’t replenished while running, you’ll be more likely to suffer from health risks associated with prolonged exposure to hot and humid conditions.

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3. Wear Light-Colored, Breathable Clothing

Light-colored and breathable clothing can help keep runners cool while exercising in humid weather. Light colors such as white, light gray, and yellow tend to reflect the sun’s rays, keeping the body temperature lower.

In hot and humid conditions, it is also advisable to opt for fabrics that are sweat-wicking to allow for faster evaporation.

icon run

Pro Tip:

Consider quick-drying fabrics like polyester or spandex, which allow for air vents in between layers of fabric. UV protective clothing is also recommended to protect against UVA/UVB exposure from direct sunlight when running outside.

4. Monitor Your Heart Rate

Your heart rate will naturally rise during humid runs. It should be monitored very closely so that you can stay within a safe zone without overworking yourself or getting overheated.

By keeping track of your heart rate while running, you’ll be able to quickly identify signs of overexertion or dehydration early on and make any adjustments necessary so you don’t push too hard.

Runner keeping track of heart rate while running

5. Recognize Signs of Heat-Related Illnesses

Heavy sweating, cold and clammy skin, a fast and weak pulse, nausea or vomiting, and muscle cramps are all signs of various levels of heat-related illnesses, from mild dehydration to severe heat stroke.

Early warning signs of heat exhaustion include muscle cramps, headaches, lightheadedness, dizziness, fatigue, and an increased heart rate. Advanced symptoms can include a rash and swelling (especially around hands and feet), weakness, and headache.

Frequently Asked Questions About Humidity and Running

Is It Harder to Run in Humidity?

Humidity can certainly make running more difficult than in dry conditions. This extra load causes the heart rate to rise, and breathing becomes a bit labored due to the higher levels of moisture content in the air, leading to an increased feeling of fatigue.

Is It Bad to Run in 90% Humidity?

Running in high humidity can be quite challenging for a lot of people. With 90% humidity, there will be a lot of moisture in the air, which makes it hard to successfully regulate your core temperature while running.

Does Humidity Make It Harder to Breathe When Running?

Yes, running in high humidity can make it harder to breathe. Humidity impairs the body’s ability to dissipate heat and leads to increased sweating and discomfort. Those with asthma or allergies may experience constricted airways while running in humid conditions.

Does High Humidity Make You Run Slower?

Yes, running in high humidity can cause you to run slower. When the air is thick with moisture, there’s less oxygen available for your body to draw from as you run. This decreases performance and leads to a decrease in speed and an increase in effort output.

Final Thoughts on Running in Humid Weather

Running in hot and humid weather conditions can be a challenge. From the risk of dehydration to heat-related illnesses, it is important for runners to take precautions against the dangers associated with running in high humidity levels.

To better prepare themselves, you should focus on proper hydration before and during runs, wear sunscreen and breathable clothing to protect against the sun’s rays, and replenish electrolytes lost through sweat.

These considerations will help ensure your safety while still being able to enjoy a good run.
Do you run in high humidity? Please share your experience in the comments below.

Also Read:


  1. Che Muhamed AM, et al. The effects of a systematic increase in relative humidity on thermoregulatory and circulatory responses during prolonged running exercise in the heat. Temperature (Austin) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5079215/
  2. Knechtle B, et al. The Role of Environmental Conditions on Master Marathon Running Performance in 1,280,557 Finishers the ‘New York City Marathon’ From 1970 to 2019. Front Physiol. 2021;12:665761 https://www.frontiersin.org/articles/10.3389/fphys.2021.665761/full
  3. Mark Hadley. Temperature + Dew Point For Pace Adjustments http://maximumperformancerunning.blogspot.com/2013/07/temperature-dew-point.html
  4. Gibson OR, et al. Heat alleviation strategies for athletic performance: A review and practitioner guidelines. Temperature (Austin). 2019;7(1):3-36 https://www.tandfonline.com/doi/full/10.1080/23328940.2019.1666624
  5. Booth J, et al. Improved running performance in hot humid conditions following whole body precooling. Med Sci Sports Exerc. 1997 Jul;29(7):943-9. https://journals.lww.com/acsm-msse/fulltext/1997/07000/improved_running_performance_in_hot_humid.14.aspx

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