November 3, 2026

What should the humidity be in a house

Humidity in your home can greatly affect air quality. But how do you know what the ideal humidity level should be in your home? What can you do to lower or raise the humidity level? Learn how to measure and maintain the proper humidity level to keep your home comfortable and healthy for you and your loved ones

Living room with a hygrometer showing a humidity level of 48%

	At a glance The humidity level in a home should generally be between 30% and 50%. A hygrometer allows you to measure the relative humidity of the air. A humidity level that is too high can lead to condensation, mould, and damage to materials. A humidity level that is too low can cause discomfort and damage wooden floors or furniture.

What is humidity?

Humidity refers to the amount of water vapour in the air. When humid air comes into contact with a surface that is cold enough, the water vapor can condense and form droplets.

Unfortunately, humidity levels that are too high or too low can cause problems in your home. In rooms that are too humid, bacteria, fungi, mould, and dust mites can thrive.

If the air is too dry, it can damage furniture and interior walls, and cause skin and respiratory problems.

How to measure humidity levels in your home

You can measure humidity levels in your home with a hygrometer, a relatively inexpensive device sold at most home renovation centres and hardware stores.

A hygrometer measures the relative humidity of the ambient air—that is, the amount of water vapour in the air compared to the maximum possible amount. Using a hygrometer, you can measure the humidity level in each room to identify problem areas.

It’s especially important to regularly check less-used areas such as the attic and basement. Make sure these areas are properly insulated and weatherproofed, as they are prone to moisture problems.

Hygrometer on a desk showing a humidity level of 52%

What is the ideal humidity level in a home?

According to Health Canada, the humidity level in a home should be above 30% in the winter and should not exceed 50% in the summer. Ideally, it should always remain between 30% and 50%. Of course, the humidity level in a home varies depending on the outside temperature, but you can maintain it at an optimal level year round by monitoring the humidity percentage.

It’s important to remember that warm air holds more moisture than cold air. As a result, a humid room will feel warmer than a dry room, even if the temperature is the same. In addition, by controlling the humidity level, you can use your heating and air conditioning systems more efficiently.

Ideal humidity levels by season
Situation	Target level	Signs to watch for
Winter	About 30%, to be adjusted based on the outdoor temperature and the presence of condensation	Condensation on windows, excessively dry air, static electricity
Summer	Less than 50%	Musty odour, condensation, stains, and damp materials
Year round	Generally between 30% and 50%	Persistent deviation, condensation, or material deterioration

Maintaining an ideal humidity level offers the following benefits:

Limits conditions that promote mould growth
Reduces condensation on cold surfaces
Protects the home’s materials and contents from prolonged exposure to moisture
Reduces the discomfort associated with excessively dry or humid air

	Tips and tricks Don’t rely solely on the number displayed on the hygrometer. If condensation appears on windows or other cold surfaces, the humidity level may be too high for the conditions inside your home.

Signs that the humidity level is too high

No matter what your hygrometer reads, certain signs don’t lie. Here are a few:

A musty or damp odour in certain rooms of the house
Peeling wallpaper
Flaking paint
Damp walls
Crumbling stucco
Fog or condensation on windows, mirrors, or pipes
Dark spots or discolouration

The dangers of a home with excessive humidity

Excessive humidity can affect both the health of the occupants and the condition of the home. Here are the main risks you should be aware of.

Risks to occupants

If you notice one or more of these signs, act quickly. High humidity levels can create an environment conducive to the growth of bacteria, fungi, mould, and dust mites. According to Health Canada, exposure to humidity and mould is associated with eye, nose, and throat irritation; coughing; wheezing; and worsening asthma symptoms.

Risks to your home

If moisture problems aren’t addressed quickly, they can worsen and damage building materials, and even certain structural components of the home. Walls are generally made up of different layers designed to control water infiltration as well as the movement of air and water vapour. When moisture accumulates in a wall or a material remains damp for too long, it can lead to mould, rot, corrosion, and material deterioration. It is therefore important to quickly identify and correct the source of the problem.

How to reduce humidity in a home

If you think the humidity level in your home is too high, here are a few steps you can take:

Improve air circulation: to do this, turn on all the exhaust fans in the house and make sure they vent air directly outside. Make sure all vents, especially exhaust vents, are unobstructed so that air can circulate freely throughout your home. Leave about 5 cm between exterior walls and furniture to minimize condensation.

Improve insulation and airtightness: check window seals, weatherstripping, and insulation to identify air leaks or cold spots. Better insulation and weatherstripping can reduce the risk of condensation on cold surfaces.

Use a dehumidifier: a dehumidifier is one of the simplest ways to quickly and effectively remove moisture from the air. Choose a unit suitable for the room’s size and monitor the humidity level using a hygrometer. Various types of units are available. You can even have a central dehumidifier installed in your HVAC system. A dehumidifier helps control indoor humidity, but it does not replace fixing a leak or a broken pipe, for example.

Check and clean the air filters: if the filters in your HVAC system are dirty, they can prevent air from circulating freely throughout your home. Clean or replace them regularly to optimize ventilation. When using the dryer, be sure to clean the lint filter after each cycle and check that the exhaust vent isn’t blocked.

Limit humidity in the bathroom and kitchen: turn on the bathroom fan when you take a shower and opt for shorter showers. If your home is already too humid, also avoid drying your clothes indoors, especially in the basement. If you must do so, choose a well-ventilated room. Always turn on the range hood and put lids on pots and pans when cooking.

Check the exterior of the house: keep gutters and downspouts clean so that water flows away from the foundation and make sure the ground slopes away from the house. Regularly inspect your roof for signs of water infiltration.

	Tips and tricks If humidity levels remain high despite the measures you’ve taken, this may indicate an underlying problem. Look for the source—such as water infiltration or a ventilation issue—rather than simply trying to reduce the humidity in the room.

Signs that the humidity level is too low

It’s harder to control humidity levels in the winter because cold air doesn’t hold as much moisture as warm air, and warm air can be very dry. Here are some signs that the humidity level in your home is low:

Dry or irritated skin
Dry cough
Dry nasal passages or nosebleeds
Dry eyes
Frequent static electricity shocks
Gaps or cracks that may appear in certain wooden elements, such as floors

How to increase humidity in a home

If the humidity level in your home is too low, there are a few steps you can take to restore a more comfortable level:

Use a humidifier: this is the simplest and most controllable way to increase humidity. Choose a portable humidifier suitable for the size of the room and clean it regularly according to the manufacturer’s recommendations.

Add houseplants: they can slightly increase the humidity in the room, particularly through the evaporation of water from their soil.

Leave a container of water in a room: the water evaporates gradually and adds a little moisture to the air. Choose a vase or decorative container and place it safely away from electrical appliances. You can add citrus peels, vanilla, or essential oils to diffuse a pleasant scent.

Consider an energy-recovery ventilator (ERV): if you’re replacing your air exchanger, keep in mind that an ERV transfers both heat and moisture between the outgoing and incoming air. A heat-recovery ventilator (HRV), on the other hand, transfers only heat.

	Tips and tricks Humidify, but don’t overdo it: keep an eye on your hygrometer and reduce humidification if condensation appears on the windows. Even when the air is dry, continue to use the range hood and bathroom fan to remove moisture from these rooms.

Maintaining a comfortable humidity level in your home year round

The humidity level in a home changes with the seasons and outdoor conditions. The key is to find a balance that promotes both the comfort of the occupants and the preservation of the home. To prevent problems before they become more serious, be sure to maintain your home properly. If a problem persists or its source is difficult to pinpoint, consulting a professional will provide you with recommendations tailored to your situation.

FAQ

1. Where should you place a hygrometer in your home?

The hygrometer should be placed in an area representative of the room, away from windows, air vents, heating units, or direct sources of steam.

2. Why is there condensation even though the humidity level is normal?

Condensation forms when moist air comes into contact with a cold surface. Outdoor temperature, insulation, and ventilation can therefore contribute to its formation, even when the humidity level seems acceptable.

3. When should you call a professional?

A professional assessment may be recommended when humidity persists, the source remains unknown, or water infiltration, mould, or damaged materials are observed.

The information provided in this article is for informational purposes only and does not constitute financial, legal, professional or other advice or opinions. As such, we make no warranties, express or implied, as to the accuracy, reliability, integrity or exhaustiveness of this information, which you use at your own risk. In no event shall Centris be held liable for actions made on the basis of the information contained in this article or for any damage or loss, direct or indirect, that may result from, or in connection with, the use thereof. We recommended consulting with industry professionals for personalized advice before making any decisions.