(Last Updated On: April 25, 2023)

Does Humidity Make Allergies Worse?

Humidity–the amount of water vapor in the air–can impact those who suffer from allergies. Too much or too little humidity can exacerbate allergies. Humidity varies depending on the season, the weather, and the location of your home. Ideally, the humidity level in your home should be between 30 – 50 percent. High humidity in your home can cause condensation on walls, floors, and other surfaces. Higher condensation levels can trigger the growth of dust mites and molds that can cause allergy flare-ups. At the same time, low humidity can irritate your nasal passages and throat. The goal is to maintain an optimal humidity level to keep allergy symptoms at bay.

woman sneezing

Humidity Levels Affecting Allergy Symptoms

Humidity can affect allergies in different ways, depending on the individual. For some people, high humidity can worsen their allergy symptoms by trapping moisture and pollen in the air, which makes it easier for them to breathe in and irritate the sinuses. On the other hand, low humidity may dry out nasal passages and make it harder to clear mucus from the nose, which can make allergy symptoms worse. In general, keeping relative humidity between 40% and 60% indoors can help reduce allergy symptoms. Controlling indoor humidity levels with a dehumidifier or humidifier can be beneficial for those with allergies. Additionally, keeping windows closed during high-pollen times of day, such as early morning or late afternoon/early evening, will also reduce exposure to pollen and other allergens in the air.

Seasonal shifts can cause allergy sufferers to experience a range of unpleasant symptoms, such as sneezing, watery eyes, and runny noses. But what many don’t realize is that the weather plays a major role in exacerbating these reactions. Rainy weather conditions create ideal breeding grounds for allergens like pollen and dust mites, while mold spores thrive in damp environments.

When humidity is elevated, it can create a conducive environment for dust mites to thrive and cause allergic reactions in those who are sensitive. Relative humidity above 50 percent encourages dust mites to proliferate, which then triggers allergic responses in some people who have sensitivities to them. Additionally, when the air becomes too humid it restricts airflow through nasal passages, making it difficult for allergy sufferers to breathe properly. 

Air Quality Index (AQI) Explained

The AQI is a helpful resource for those with seasonal allergies, providing an indicator of the air quality in their region. The AQI measures five major pollutants, such as ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide to create an overall index value that gives you an indicator of the quality of your local air. Each pollutant has an index value; when combined, they create the overall AQI number.

At lower levels, the AQI generally indicates good air quality; at higher levels, it can be dangerous to breathe without protection such as masks or respirators. It’s important to know what each level means so you can make informed decisions about protecting yourself from poor air quality days:

Good: 0 to 50 represents clean outdoor air and minimal risk for allergy sufferers and other respiratory issues like asthma attacks. AQI readings in this range typically indicate clean air and minimal risk for allergy sufferers or those with respiratory issues such as asthma. 

Fair: 51 to 100 is a moderate to high range, and it is advisable to take extra precautions. People with sensitive systems should consider avoiding outdoor activities or donning protective masks while outdoors to avoid any potential irritation. Those with existing conditions such as asthma should take extra precautions due to the increased risk of respiratory difficulty. 

Control Indoor Air Quality

Proper humidity levels should be maintained. High humidity levels can encourage dust mites to thrive in a home environment while also making it difficult for allergy sufferers to breathe due to congestion in the mucous membranes. You can measure the relative humidity in your home with a hygrometer, which is an instrument that measures moisture content in the air. If the relative humidity level is above 60%, it’s considered high and could be making your allergies worse. A whole-home humidifier or dehumidifier can help you maintain relative humidity levels between 30-50 percent, which is optimal for managing allergies. There are several ways to reduce indoor humidity levels, such as using a dehumidifier or air conditioner or installing a ventilation system.

When it comes to humidifiers, there are several types available on the market – evaporators, warm mist humidifiers, central humidifiers, and cool mist humidifiers – all of which work differently to control humidity levels indoors. It’s important to choose one that suits your needs and environment best.

it’s important to keep your humidifiers clean to keep them free of mold and bacteria. The Mayo Clinic has tips to keep portable humidifiers clean, including using distilled water, changing the water often, and rinsing the tank after cleaning. They recommend cleaning humidifiers every three days.

Routine cleaning of the ducts in your home is also a key element in enhancing the air quality in your residence. Indoor air quality improvement services can help to reduce dust mites, pollen, mold spores, and other common allergens that may be present in your home’s air. By removing dirt and debris buildup inside HVAC systems, these services can prevent contaminants from circulating throughout your living space. 

In addition to using a humidifier or dehumidifier, another option is using an air purifier with a HEPA filter to help capture allergens like pollen from circulating in the air inside your home. This will help keep allergens at bay and maintain a healthy level of indoor humidity by eliminating airborne particles that could contribute to increased moisture levels in your home.

Frequently Asked Questions: Does Humidity Make Allergies Worse?

Do Allergies Get Worse with Humidity?
Allergies can worsen with increased humidity. Allergens such as dust mites and mold thrive in moist environments and are more likely to trigger allergic reactions when the air is humid. High levels of humidity also make it harder for mucous membranes to filter out allergens, making people more susceptible to an allergic reaction. 

Can High Humidity Cause Allergy Symptoms?
When humidity is elevated, it can create an environment conducive for dust mites and mold growth to thrive and cause allergic reactions in those who are sensitive.

Is High Humidity or Low Humidity Better for Allergies?
Low humidity is generally advantageous in diminishing the presence of potential allergy triggers, such as dust mites and mold spores. Additionally, low humidity helps keep nasal passages clear by reducing mucus production and promoting easier breathing. However, when indoor humidity is less than 30 percent, it can cause dry nasal passages that can exacerbate allergies.

Does Humid Air Help with Allergies?
Relative humidity above 50 percent encourages dust mites to proliferate, which then triggers allergic responses in some people who have sensitivities to them. Also, when the air becomes too humid it restricts airflow through nasal passages, making it difficult for allergy sufferers to breathe properly. 


In conclusion, high humidity can worsen allergies and make it difficult to breathe. To combat this, choose the right clothing material when going outside, reduce your exposure to fungus, mold and pollen outdoors, use natural cleaning products and adjust your diet. By following these tips and taking extra caution when it comes to managing your allergies in high-humidity environments, you can reduce symptoms and live a healthier life.

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