What Is Humidity?

Humidity is the term for the gaseous water content in the air. The quantity of gaseous water (water vapor) in the atmosphere is known as HUMIDITY, which can change when water is present in excess amounts. For example, when it is about to rain, there is a lot of water vapor in the air.

Where does Humidity come from?

There are many factors that decide the humidity of a place, both indoors and outdoors. Temperature plays an important role in deciding the relative humidity indoors as well as outdoors. For example, when the temperature is hot, the humidity decreases as the air can hold more water content; but when the temperature decreases, the air cannot hold much moisture, and the relative humidity increases. Therefore, when the temperature indoors is cold or hot enough, we need to warm or cool it up, respectfully, to maintain the ideal humidity levels. When there is 100% humidity in the air, it will rain as the air won’t be able to hold more water vapour.

What is the difference between
Relative Humidity & Absolute Humidity?

Relative Humidity

The ratio of the amount of water vapour in the atmosphere to the highest amount of vapour that the air can hold is known as relative humidity.

Absolute Humidity

Whereas the quantity of water vapour present in a particular amount of air at a given time and temperature is known as absolute humidity.

humidity icon


Are humidity and moisture the same?

Humidity is the amount of water vapour in the air in its gaseous state. Whereas moisture is the content of water in its liquid state. When air reaches its limit to absorb water in the form of water vapour, water will begin to condense as drops in the air that is why clouds form. That is known as moisture. When humidity reaches its peak, rainfall happens, that is moisture.

Factors that affect Humidity Level
Indoor & Outdoor

Outdoors Environment


humidity due to air movementAir Movement

Higher wind speeds result in less water evaporation and lower humidity, while lower wind speeds result in more evaporation & higher humidity.



humidity due to temperatureTemperature

The air can store more water vapour when the temperature increases, hence a warmer atmosphere may have a higher humidity level.



humidity due to wind speedWind Speed

Lower wind speeds result in more water evaporation & higher humidity, while higher wind speeds result in less evaporation & lower humidity.



The humidity will rise the longer it rains because the air is constantly absorbing water.



humidity due to air pressureAir Pressure

Humidity depends on the atmospheric pressures at different geographical locations, temperature, and air pressure in the respective area.

Indoor Environment


humidity due to cooking or boiling waterCooking or boiling water

Cooking and water boiling activities release water vapour in the air. This will add to the relative humidity of that room.




gas heaterAppliances such as Gas Heaters

One litre of moisture is produced every hour while using a non-fueled gas heater.



ventilation rateVentilation Rate

High humidity indicates inadequate ventilation. Extremely high indoor humidity is linked to an increase in the development of bacteria and mould.



humidity due to drying cloths indoorDrying the clothes indoors

Drying the clothes indoors can increase the relative humidity of a room and therefore will increase the risks of mould and bacteria growth.



water leakagesWater leakages

Water leakages can increase both moisture & humidity. As a result, the air will become stale & the chances of getting sick due to bacteria will increase.

What Happens When Humidity Level
Is Very Low & High?

The ideal or healthy range of humidity should be maintained between 30-60%. Humidity is unhealthy
when it exceeds or is lower than the ideal limit, it causes many discomforts and
can result in the growth of mold and bacteria.

When humidity is high (> or = to 60%)


Encourages Mold & Mildew due to high humidityEncourages Mold & Mildew

When relative humidity is more than 60%, it can promote the growth of mold and mildew. Certain types of toxic molds can seriously impact one’s health, for example, black mold is considered very dangerous for humans.



virus and bacteria due to high humidityVirus and bacteria

When you spend too much time in too humid conditions, it might trigger allergies & make you sick. Viruses and bacteria thrive in humidity above 60% which can cause various respiratory illness symptoms.



excess sweating due to high humidity
Excess Sweating

Humidity means that the air contains water vapour. When the air becomes more humid, people experience excessive sweating as the sweat will not evaporate easily or will take more time than usual due to high water vapour in the air.



increase respiratory due to high humidityIncreased Respiration

Due to high temperature, when our bodies heat up naturally, we sweat. That sweat then evaporates to keep our bodies cool. Due to excess moisture in the air, our bodies need to work harder to cool off. This increases blood circulation and respiration.




wall damage due to high humidityDamage Your Belongings

High humidity can damage your furniture, floorings, wallpaper, paintwork, etc. High humidity results in condensation that gather on your walls. So, the paint will start to flake and the wallpaper will curl up.

When humidity is low (< 30%)


virus and germs due to low humidityGerms and Viruses

Due to low humidity, germs & viruses disperse, and travel around freely. As a result, they thrive in low humidity, and diseases such as RTIs are more common when relative humidity is low.



sceptibility to respiratory due to low humidity
Susceptibility to respiratory diseases

Low humidity and low temperatures result in more susceptibility to catching respiratory diseases, colds, and many other respiratory tract infections like sinusitis, otitis, bronchitis, and pneumonia. This is because low humidity will result in drying out the airways.



dry skin due to low humidityDry Hair and Dry Skin

When the air has low humidity, skin, and hair do not retain or get enough moisture. As a result, the skin will flake resulting in skin irritation and itching and can worsen skin conditions like eczema and psoriasis. Whereas hair will become more dry, frizzy, dull, and will break more often.


influenza due to low humidityInfluenza

Low relative humidity results in chances of spreading influenza. Low humidity further reduces the ability of cilia (hair-like structures in the airway cells) in removing viruses such as Covid 19 and preventing damage done to the lungs due to such viruses.




low performance of student due to low humidityDecreased performance

Even minor variations in relative humidity and temperature can create measurable changes in your abilities to concentrate or accomplish tasks, especially in places like schools and offices where concentration is extremely important.

How To Maintain the Good Humidity Indoor?

Healthy or ideal indoor relative humidity levels should be between 30-60%.

fix leakage or any pipe leak

Fix any leakages or pipe leaks

Fix any broken pipes, faucets, and leakages that can result in more moisture and condensation indoors.

dry cloths outside


Dry your clothes outside

It’s recommended to dry your laundry outdoors as they can increase the relative humidity of a room if dried indoors.

relocate indoor plants


Relocate your indoor plants

If the relative humidity of a room is higher and it has plants in that room, consider relocating them as they are a potential source.

use a dehumidifier


Use Dehumidifiers

Dehumidifiers will help you reduce the relative humidity of your space if you have high humidity problems in your room.

use charcoal pieces

Use charcoal pieces

Charcoal is a great absorber. A single piece of charcoal can reduce humidity levels in your air. They just need to be replaced every 2-3 months.

open windows

Open windows

Opening windows in areas with high humidity such as bathrooms is one of the easy solutions. This will increase ventilation as well.

Humidity levels and what do they mean?

Healthy or ideal indoor relative humidity levels should be between 30-60%


Humidity Level What does it mean?
= 70% Dust mites, the most common dust allergens for asthma, thrive when relative humidity is at or above 70.
30-60% Ideal relative humidity indoors.
>30% Low relative humidity. Increases the chances of catching airborne viruses. Eye, nose, and throat dryness.


Healthy or ideal indoor relative humidity levels should be between 30-60%. Humidity levels >= 70% promote the growth of dust mites, the most common dust allergens for asthma, and they thrive when relative humidity is at or above 70. Humidity levels below 30% mean relative humidity is low that increases the chances of catching airborne viruses. Eye, nose, and throat dryness.


WHO Guidelines of Humidity

Measure Risk Estimate
Self-reported humidity – 2.71 (1.07–6.91) for cold
– 3.02 (1.14–7.98) for sore throat
Signs of high humidity – 3.97 (3.74–4.22)
Absolute indoor humidity > median, 5.8 g/kg – 1.7 (1.0–2.9)
Relative humidity > 45% – 0.8 (0.4–1.5)
Absolute indoor humidity level – > 5.8 g/m3, 2.0 (1.2–3.4)




Choose Your Air Quality Monitor To
Measure Humidity Level