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What Humidity Level is Uncomfortable?

Last updated January 11, 2023

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Author avatar James Booth

As an experienced content producer and editor, James makes sure our content is always compelling, clear, and useful. He also leads the production team and makes sure our writers have everything they need to keep doing their best work. On his off days, you'll find him outside hiking or searching for stone circles.

Our verdict:

Humidity levels are measured by the relative humidity and the dew point. The latter will be how humidity feels for you. 

When humidity and dew points reach certain temperatures, the moisture in the air will be at a higher concentration, negatively affecting your comfort levels. They can even affect your overall general health.

While there is no set humidity upper threshold, the National Oceanic and Atmospheric Administration (NOAA) typically considers relative humidity levels of 50% or more and dew points above 65% to be uncomfortably high.

Even for those who are used to warmer climates, humidity is an entirely different beast. And while we often associate humidity with the outside environment, it can also be humid inside your house- which can pose several health risks!

But what is humidity and why does it affect our comfort levels? In this article, we’ll go for a deep dive into the murky waters of humidity and dew points and how to combat it when it all gets to be a bit too much.

What Exactly is Humidity?

The air around us is made up of a mixture of different gases. These include nitrogen, oxygen, argon, carbon dioxide and water vapor. Water vapor is generally invisible to the human eye, but in situations with high concentrations, you may see a haze or fog. This concentration of water vapor in the air is known as humidity. 

When the humidity is high, water vapor in the air is high. In these circumstances, it will feel wetter outside as the air becomes packed with moisture. 

You may be used to seeing humidity described as ‘relative humidity’ (RH) in weather reports. This refers to the amount of water vapor held in the air. The RH is the amount of moisture present in the air compared to the maximum amount that the air can contain at the same temperature. This ratio is expressed as a percentage.

For example, if the air outside was -10ºC (14ºF), the maximum amount of moisture the air could hold at that temperature would be 2.2 grams of water per cubic meter. If there were 2.2 grams of water per cubic meter at this temperature, this would be 100% RH. If, however, there were only 1.1 grams of water per cubic meter at this temperature, this would make it 50% RH. 

You may also see the term ‘dew point’. This refers to the temperature to which air needs to cool down to become saturated with water vapor.  When it has cooled below this temperature, the moisture capacity is reduced- and that’s when the water can condense, forming dew. When the RH reaches 100%, dew appears.

Why is Humidity So Uncomfortable?

At higher concentrations of humidity, the air around you becomes packed full of water vapor. There is little room for anything else when the air is in this state. Typically, in hot temperatures, your body sweats and the air evaporates the sweat, which results in cooling you down. Your skin relies on the air to get rid of moisture. 

However, in high humidity, when you sweat, the air is already so full of water that it cannot absorb anymore. This means that instead of evaporating off you into the air, the sweat stays on your skin- preventing your body from regulating its temperature.

Of course, humidity is not just an issue for your body’s temperature regulation but also in your home. High levels of humidity in your home can cause mold, as well as issues with household electronics. Bathrooms are usually a key problem area due to the moisture and steam from baths and showers.

What to Put in Google to Find Out Humidity Level

So, now the question becomes: How do you work out which measure—dew points or RH—is the most important one to Google for when you want to work out how you’ll feel?

Let’s imagine that you open up your weather app. It says that the RH is only 60%—a relatively average amount—but once you head outside, the air feels so muggy you find sweat pouring down your face! In contrast, you recheck your app the following day, and the RH is at 100%. However, once you head outside, you must grab a coat. 

What’s going on here?

Well, RH is relative to the temperature of the air. 

While the RH maybe 100%, the temperature could be 26ºC (80º) or -6ºC (20ºF). No matter what the RH is at that low a temperature, it’s doubtful that the air will feel muggy. However, if the temperature is 26ºC (80ºF), but the humidity is only 60%, it will feel humid. This is because the dew point is sitting at 18ºC (65ºF).

As discussed, dew points tell you the actual amount of water vapor in the air, so the dew point measurement is an absolute measure of the amount of water vapor present. The higher the dew point, the more moisture there will be. 

Knowing all this tells us that dew point is the best indicator of how you will feel and your comfort levels. If the dew point is high, it will be muggier and you’ll feel more uncomfortable. RH here is defunct when figuring out how humid the outside air is.

When Googling, try searching for “dew point now” to see the current dew point in your location. 

The top hit will likely be https://www.accuweather.com, which has a handy chart telling you the dew point. Alternatively, you could use the dew point calculator found at: http://www.dpcalc.org.

What Humidity Level is Considered Uncomfortable?

Our handy table shows you what dew point temperatures will cause you to feel uncomfortable.

DewpointHow it feels
40°Nice summer day
50°Comfortable
60°Uncomfortable
75°Unbearable

A quick rule of thumb is that the closer the dew point is to the air temperature, the more likely the air will feel relatively humid. However, the air temperature will affect your perception of humidity, so you may not always feel this.

Health Effects of Humidity

While moisture is unpleasant, it can become dangerous when paired with extreme heat. When you experience high humidity within the home, this creates excess moisture and condensation. 

This can lead to mold or rot, which can have serious health consequences. In addition, it could also cause damage to your home, which could be costly.

On the other hand, it can also be harmful when the humidity is too low. Low humidity has been linked to the spread of certain viruses, such as cold, flu and even Covid-19. This is because the mucous membranes within your respiratory tract become inflamed and dry out in low humidity.

Some of the side effects you may experience from humidity include:

😩 Headaches

😵‍💫 Dizziness

🤢 Nausea and vomiting

😮‍💨 Elevated breathing and exacerbation of asthmatic symptoms

🥵 Excessive sweating

💦 Dehydration

🔥 Heat rash and heat stroke

😴 Disrupted sleep patterns

💡 Pro tip: Depending on your situation, you may want to look into purchasing either a humidifier or dehumidifier.

How to Beat Humidity Indoors

In high humidity, what can you do indoors to stay cool? Here are our top tips:

1. Don’t open the windows — Opening windows when it’s hot and humid won’t help to cool the house down. It can make it feel worse, as well as increase the likelihood of mold and mildew occurring.

2. Invest in a dehumidifier — Dehumidifiers are excellent and safe devices that work to reduce indoor humidity.  While they won’t clean the air like air purifiers, they will work to condense the moisture in the air around you into a handy tank, which you can then pour away down a drain. 

3. Put a timer on your showers and keep them cool — In high humidity, you want to ensure that you aren’t adding excess moisture into your environment. Keep your showers to 10 minutes or less in a cooler temperature, use a dehumidifier in the bathroom and ventilate to allow any steam to escape.

4. Use an air conditioning unit — An air conditioning unit is a better option here than a fan, as the fan will move the humid air around. In contrast, the air conditioning unit will help to decrease the temperature.

5. Use moisture-wicking sheets when you sleep — On humid nights, heavy sweating is quite common. Sheets made from cotton or bamboo will wick the moisture away from your body and are more breathable than synthetic sheets. These all have the effect of cooling your body down and helping you feel more comfortable.

💡 Pro tip: For more ideas, check out our post on how to naturally dehumidify your home.

How to Beat Humidity Outdoors

Can’t stay indoors in the high humidity? Here are our top tips for tackling humidity when you’re out and about:

1. Don’t overexert yourself outdoors — If you need to exercise, try to find an indoor location, or keep your outdoor period to a minimum. Be sure to bring plenty of water to keep yourself hydrated.

2. Wear loose and light clothing — There’s nothing worse than tight or thick clothing in a hot and humid environment. Go for cotton, linen and loose, flowing material. The air will circulate better, and you’ll feel much more comfortable.

3. Stay out of the sun at midday — When at its hottest, you’re more at risk for the more severe side effects of humidity and high heat. Stay inside, preferably in air conditioning!

4. Remember to hydrate — It’s easy to dehydrate when it’s humid, so don’t forget to bring water and plenty of it. 

💡 Pro tip: if you freeze your water bottle on its side, it’ll melt slowly throughout the day, providing you with cold water!

5. Hang out somewhere with air conditioning — Here are some suggestions to get you started: 

🛍️ Mall

🎥 Cinema

📚 Public library

🏊‍♀️ Museum

☕ Café or restaurant

Final Thoughts

Even for the seasoned warm weather pro, high humidity can be a real killer. Remember, it’s the dew point that will directly affect how comfortable you feel, so Google this before you head out and about for your day! It’s essential to be extra careful in high humidity and heat, as this combination can have disastrous results. Similarly, low humidity can be a catalyst for an increased spread of viruses.

If you have issues with either excess moisture or the opposite in your home, consider investing in a dehumidifier or humidifier. These tools can help you to regulate your home’s humidity levels.

SOURCES

Air Things. (2021). How Humidity Damages Your Home- And How To Fight It airthings.com 

Health Partners. High Humidity Is Uncomfortable, But Can It Make You Sick? healthpartners.com

How Stuff Works. (2021). What Is Relative Humidity and How Does High Humidity Affect How I Feel Outside? Science.howstuffworks.com

National Geographic. Humidity. nationalgeographic.org

National Weather Service. Dew Point vs. Humidity weather.gov 

Sleep Foundation. (2022). Humidity and Sleep sleepfoundation.org

Wikipedia. Dew Point wikipedia.org

Wikipedia. Humidity wikipedia.org