What Is Considered Low Humidity

Very dry and very humid spaces usually cause us a certain level of discomfort. Those who suffer from asthma or allergies know that indoor humidity level is a significant factor in maintaining good health. When the humidity in a home is high, it can cause mold in your home, which can be extremely unhealthy to breathe in and be around. On the other hand, very low humidity levels are harmful to the throat, nose, and eyes, as they may become highly irritated. Also, high humidity is a common reason behind structural damage, as many materials we use in our homes are not humidity-resistant.

So what is considered low humidity?

What is Considered Low Humidity?

Humidity is commonly considered too low if the level goes below 30%. However, if it rises above 55%, we usually consider it too high.

Humidity over 65% can make the air feel sticky and oppressive, as there is too much moisture. After it crosses 70%, humidity starts sticking onto the objects, and you can literally feel it on your skin and observe how small drops are forming on the surfaces.

Usually, when the temperature is somewhere between 0 and 10 degrees Fahrenheit, we can expect the humidity to fall below 30%. And for the interval between -10 degrees Fahrenheit and 0 degrees, the humidity levels are usually below 25%.

Going to extremes, if the temperature falls somewhere between -10 degrees Fahrenheit and -20 degrees, the humidity levels can reach as low as 20%. Finally, below -20 degrees Fahrenheit, which is an extraordinary low temperature that not many places on Earth reach, the indoor humidity will be below 15%, which is very unpleasant for the skin and throat. Spare a thought for those warehouse workers working in the freezer section.

How Does Low Humidity Subjectively Feel?

Despite the mentioned health effects such as dry skin, throat, and eyes, low humidity also affects our subjective perception of how hot it is.

Usually, low humidity leaves the impression of colder air. On the other hand, piled-up vapored water in the air makes the indoor temperature feel warmer.

Health Issues that Occur Due to Low Humidity

So far, we mentioned only eyes, skin, and throat. However, several types of health issues can occur due to dry air (low relative humidity level). For example, a general increase in susceptibility to illness and colds, especially of the respiratory type. Due to your mucosa becoming drier, it is harder for it to defend you from bacteria and other microorganisms that may enter through your mouth or nostrils.

Some people experience more frequent nose bleeds, enhanced symptoms of flu or cold, as well as stronger allergic reactions, especially if we are talking about allergic asthma. High humidity can also be challenging for people suffering from asthma.

The Difference Between Absolute and Relative Humidity

Absolute humidity levels usually refer to how much moisture there is in the air in general. It’s the number of grams of water vapor per cubic gram in the atmosphere or in the air, no matter the temperature. The more water there is in the air, the higher the absolute humidity will be. Basically, what we perceptive as moisture in the air is this absolute humidity.

On the other hand, relative humidity levels depend on the temperature at the current moment and the relative amount of water that can remain in the air at that temperature. The thing is that warm air, in general, can hold more water in the air than cold air, which means that the absolute humidity might be the same in two conditions, but the relative humidity will be lower when air is warm and higher when air is cold.

What Is the Ideal Humidity Level for an Indoor Space?

As we mentioned already, humidity that goes above 50% is considered high, while the one that goes below 30% is considered very low.

This means that optimal humidity levels are between 30% and 50%, with 40% being in the golden middle.

Of course, ideal humidity is not some universal value, and it can depend on where you live. For example, if you are located in a very cold geographical area, experiencing very high humidity levels doesn’t seem very logical nor natural, while warm areas that are near the sea usually have higher humidity levels.

Furthermore, some people enjoy humid air much more than others. This can be due to habits, health conditions, or simply their background – someone who moved from a humid geographical area to a dry one might find it hard to adapt and decide to purchase a humidifier.

How to Maintain an Optimal Indoor Humidity Level?

There are many ways how the indoor humidity levels can change so that it becomes unpleasant to spend time inside either due to high or low indoor humidity levels. Luckily, this is a widespread problem, so there are also many simple solutions to it.

We will suggest here to use either a humidifier or a dehumidifier, depending on the type of problem you are facing. This is probably the simplest way to maintain your indoor humidity levels at the optimal 30-50%.

Dehumidifiers usually remove excess humidity from the air and make the indoor environment less allergens-friendly, thus reducing the amounts of dust, mold, mildew, and other problematic matters. Dehumidifiers usually come as portable machines, and they are often highly affordable, but if you are ready to invest an additional dime, you can also add a dehumidifier to your home HVAC system.

On the other hand, Humidifiers work in such a way that they actually produce water vapor and keep the indoor air moist. Some humidifiers are of the ‘cool’ type, while others are warm-mist. Each type of humidifier has its own benefits, yet, both of them are beneficial if your goal is to improve the relative humidity from low to optimal.

If the region where you live has all four seasons of the year, you may need to obtain both devices. Sometimes, in these regions, summers can be extraordinarily hot and humid, while winter temperatures can surprise you with a deep minus.


Although the subjective perception of humidity can vary, there are certain universal values that have been widely accepted as optimal. According to these measures, low humidity is anything below 30%, while optimal humidity ranges from 30% to 50%. Anything that goes above 50% is considered high humidity.

In case you are struggling with balancing out your humidity levels at home, you should perhaps try using the humidifier or the dehumidifier. Balancing out your indoor humidity levels is particularly important for maintaining good health and preserving the indoors of your home, since natural and wooden furniture is susceptible to both low and high humidity levels.