what should inside humidity be in summer

What should inside humidity be in summer? You may find this a bit confusing, but you have to learn it to avoid various issues.

The value of ensuring a pleasant and healthy indoor humidity rises dramatically as the hot summer months approach.

 In order to protect our respiratory health, maintain high air quality, and stop the growth of mold and mildew, you have to know the answer to, “what should humidity be inside home in summer?”

Ideally, the inside humidity levels should stay between 40% and 60% to ensure you feel comfortable. 

What Should Inside Humidity Be in Summer?

The Issue of Maintaining Proper Humidity Levels

No one likes to think of their home as unhealthy, but it happens when a home’s internal environment is left uncontrolled.

recommended indoor humidity level for summer

In winter, the home becomes too cold for comfort and in summer too sticky and humid.

Many homeowners monitor the internal humidity levels to keep a home healthy and avoid humidity extremes.

However, it is important to adjust the internal humidity levels of the house almost constantly according to the type of activity taking place in it and rising and falling external temperatures. 

The Role of Air in Inside Humidity

the role of air in inside humidity

The air in a home should feel comfortable to be in.

When humidity is high, occupants will find it difficult to breathe in the moisture-laden air. It’s like breathing through a wet sponge.

As well as feeling breathless, they overheat and their skin feels sticky because their sweat can no longer evaporate.

When the humidity is low, the mucus membranes of the respiratory tract dry out so breathing in dry air is just as uncomfortable.

And that is why it is essential to know the appropriate indoor humidity levels

What Should Inside Humidity Be in Summer?

ideal summer indoor humidity level

Outdoors in summer, temperatures are higher and the evaporation process works faster adding to the percentage of water present as vapor in the air.

When this humid air gets trapped indoors, it is attracted to cooler surfaces that allow the water vapor to condense out as liquid water droplets. 

If it is left the water seeps into the structure of the house as a warm musty damp that attracts harmful mold spores and wood rot.   

Identifying the Suitable Inside Humidity Levels

identifying the suitable inside humidity levels

The recommended levels of humidity in a home are measures of relative humidity.

Weather experts in weather reports use this humidity measure to describe the percentage of water vapor in the air relative to the temperature.

Its counterpart, absolute humidity, describes the amount of water vapor in the atmosphere without considering temperatures.

The recommended relative humidity range for indoors is quite broad, between 40% and 60%, so most people will feel comfortable.

Fact: The ideal humidity range easily accommodates a normal 10% seasonal variation at either end of the scale, summer or winter. 

Factors Affecting Indoor Humidity Levels 

Outside relative humidity has only a slight effect on the relative humidity levels in an airtight house.

It is our daily water-based routines that add moisture to the air in the home by the pint.

Even the air we breathe out and our perspiration add to the moisture in the air within a sealed house.

factors affecting indoor humidity levels

Any activity involving water will increase humidity, such as:

  • Cooking
  • Showering
  • Doing the Laundry
  • Watering the houseplants

Including how airtight and water-tight the home is, several other factors influence its humidity, such as:

  • Its design
  • The materials it is made from
  • Its insulation
  • The size of the air condition units it uses

Humidity levels vary throughout a house and enclosed areas like the bathrooms, attics and crawl spaces will have higher humidity levels than an open area like the lounge.

Fact: Leaking pipework, poor ventilation, and conditioning units cooling the air too quickly also contribute to fluctuating humidity levels.  

Health Benefits of Optimal Indoor Humidity 

health benefits of optimal indoor humidity

Living with high or low humidity has negative repercussions for health.

But, living in a home with optimal humidity levels goes beyond being physically comfortable and, according to extensive studies, is actually beneficial to health.

Here are some benefits of maintaining adequate inside humidity in summer: 

Prevention of Mold and Mildew

prevention of mold and mildew

Although mold and mildew spores are always present in the air, they pose problems in high concentrations causing anything from a sore throat and stuffy nose to life-threatening asthma attacks.

Between 40% and 70% relative humidity most molds and mildew spores struggle to take hold.

Therefore, in vulnerable homes, experts recommend keeping relative humidity constant at 50%.

They also recommended installing additional ventilation, fixing leaks, cleaning infected areas with strong bleach and using mold inhibitors before painting. 

Reduced Allergens and Airborne Irritants 

reduced allergens and airborne irritants

Controlling the allergens and irritants around us creates better air quality, reducing asthma attacks and allergic reactions.

Just as with spores, there are many naturally occurring allergens in the air such as fungi spores and pollen.

Indoors, dust mite feces are among many allergens contributing to poor indoor air quality.

Dust mites live in pillows and mattresses feed on dander, shed skin and thrive in humid conditions so regular cleaning is a must. 

Enhanced Respiratory Health

enhanced respiratory health

Asthma and COPD sufferers find that increasing humidity can help ease their breathing.

The effect is more noticeable as the moisture and temperature relax their respiratory systems although everyone benefits by controlling humidity in the home.

People report sleeping better, having more energy and staying healthy during the cold and flu season.

Research has concluded that effective humidity control in workplaces and publicly used buildings is a cost-effective means of reducing employee absences due to short-term respiratory sickness.

Fact: It is found that at 40% relative humidity viruses like influenza become less infectious and die. 

The Importance of Monitoring and Adjusting Indoor Humidity Levels 

To be effective, any system designed to increase or decrease humidity levels must react to constantly changing temperatures.

Although there are seasonal adjustments, they do not really affect a modern well-made home.

significance of regulating indoor humidity

It holds unless someone leaves a window open, as relative humidity levels will still rise and fall throughout the day.

As humans, we are slow at reacting to subtle changes in relative humidity. There are plants that react faster.

Therefore, it makes sense to monitor humidity levels inside your home. 

Monitoring Humidity in Your Home

monitoring humidity in your home

To monitor humidity in the home effectively we need specialized equipment.

Hygrometers have been used widely in meteorology for a very long time.

The first was invented by Leonardo de Vinci. These days, anyone can buy one for under $10.

Modern hygrometers use sensors to measure temperature and moisture and it takes seconds to get a reading.

Initially it is important to take readings over a few days in every room and at different times to get a clear picture of what is going on.  

Additional Options to Regulate Humidity

additional options to regulate humidity

Humidifiers, dehumidifiers and air conditioning are used to regulate humidity levels.

A humidifier adds moisture to the air as water vapor, some come built-in to heating and air conditioning systems.

A dehumidifier draws in water vapor lowering the relative humidity by making the air drier.

Problems occur when the units are left running, adding or subtracting more water than is healthy.

Fact: Air conditioners exchange the indoor air for outdoor air, transferring away unwanted heat and changing inside humidity levels.    

Additional Tips for Managing Humidity in Summer

With adequate ventilation most homeowners can manage the humidity levels in their homes and keep levels well in the optimal range by opening or closing a window.

Other options are available too.

For instance: 

Consider Proper Maintenance

consider proper maintenance

A little home maintenance can help too. 

Poor design and bad building can mean the vents in the brickwork to allow air to flow in and out of the structure are missing, obstructed or blocked.

 Even an electric fan can help cool the air so it circulates better. 

Restrict Water-Based Activity

Another way to control humidity in summer is to restrict water-based activity inside the house to the times of the day when the relative humidity is at its lowest.

restrict water-based activity

 Usually, in areas that experience high seasonal humidity, the air will be especially heavy with moisture by late afternoon and it rains. 

In these regions, the best time to cook, shower or dry washing is once it starts when the temperature and humidity levels are falling.

An Important Consideration

As well as checking humidity levels regularly and investing in a dehumidifier, homeowners can manage relative humidity levels around the home in summer in other natural ways.

All ferns but Boston ferns especially, absorb water in high humidity and thrive in bathrooms and kitchens.

Spider plants, begonias, peace lilies, and bamboo palms also lower humidity.

Fact: Any material that absorbs water can help lower humidity, including cat litter, wood shavings, straw, soil, cotton, sugar and salt. 


What should inside humidity be in summer?

The humidity should stay within the range of 40% and 60%, which is rather broad and easy to achieve.

But knowing what throws everything out of balance is just as vital.

Pay attention to monitoring humidity levels inside your home and then take steps to change humidity levels for a more comfortable environment.