Asthma and Allergy Forecast

The Asthma and Allergy Forecast tool uses advanced data to determine potential asthma and allergy triggers on a given day, including the pollen count today. It also provides data on the daily risk and spread of the flu virus.

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What is the pollen count today?

close-up of pussy willow tree pollen

Pollen counts measure the pollen in the air on a given day. Scientists use air sampling devices to collect particles from the air and then analyze them. They identify types of pollen as well as how much of each is in the sample. The pollen count covers a large area since pollen is airborne. It is measured by grains of pollen in a cubic meter. Government agencies, universities and commercial research institutions measure pollen counts to provide information to the public.

You can visit the National Allergy Bureau for daily pollen count information. Many local news websites and TV stations report the pollen count as well.

Pollen comes from blooming grasses, plants, trees and weeds. It is carried far and wide by the wind. You might be allergic to one kind of pollen and not another. Pollen counts vary with the weather and location. Pollen allergies differ from person to person. Symptoms may include runny nose, nasal congestion, sneezing, coughing, itchy or irritated eyes, eye swelling, postnasal drip and fatigue.

It is essential to know which types of pollen trigger your allergies. Your doctor may recommend allergy testing, such as a skin test or allergen-specific blood tests. If testing confirms a pollen allergy, work together with your doctor to develop the best treatment plan for you.

Work with your doctor to craft a treatment plan that reflects your pollen allergy. Take steps to avoid exposure to pollen and treat allergy symptoms.

What is the air quality today?

Checking the pollen count is only the beginning. Air pollution and mold spores are also problems for people with asthma and allergies.

Fine particulate matter such as emissions from factories, power plants and vehicles contribute to air pollution. When inhaled, these particles can be powerful asthma triggers. They affect breathing and lung function.

Mold spores and seeds fly through the air starting in late spring. They peak during the summer with hot, humid weather. In the fall, they grow on decaying leaves, compost piles and grasses. Windy, rainy weather during any season can send mold spores airborne.

Visit AirNow.gov for Environmental Protection Agency (EPA) air quality status and alerts. The website also has apps available for smartphones and tablets. Air quality alerts can help you plan your daily activities and manage your asthma and allergy symptoms.

How to monitor pollen season to manage allergies and asthma

Keep track of the pollen count throughout the day, every day. Pollen counts tend to be higher in the morning. Trees, grasses and weeds release pollen first thing in the morning.

Mold is present during pollen season as well. Signs and symptoms of mold allergies include runny nose, nasal congestion, sneezing, sore throat, and watery or itchy eyes. People with asthma may feel tightened airways. Even a tiny amount of exposure to mold can cause symptoms.

Changes in the weather during pollen season can also affect your asthma and allergies.

Temperature changes, humidity changes and rain and wind from thunderstorms can inflame airways. leading to asthma flares. People with respiratory conditions often breathe through the mouth. This can bring weather-related irritants directly to the lungs. It also doesn’t allow your nose to regulate the humidity and air temperature.

Pollen allergy seasons are trending toward becoming longer and more severe. This is due to changing weather patterns resulting from climate change. People with allergies may find they need to use more allergy medications to manage symptoms. Talk with your doctor about whether to adjust your treatment plan.

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How does the weather affect symptoms?

  • Humid air is moist and heavy. When the air is stagnant, air quality goes down. This makes breathing harder for everyone. It can trigger an asthma and allergy flare-up since mold and bacteria grow better in moist environments. Humid weather can worsen allergy symptoms.
  • Hot weather often impacts air quality. Ozone can rise to dangerous levels, irritating your respiratory system. Increased traffic, exhaust, smog and other pollutants can make breathing harder if you have asthma.
  • Cold, dry air may seem better for your breathing than hot, humid air. Unfortunately, breathing it in can make the bronchial tubes constrict and spasm as they try to keep airways open, making symptoms worse.
  • Thunderstorms bring barometric changes, high humidity and winds that blow pollen and mold spores everywhere. This can lead to what’s called thunderstorm asthma. In addition, lightning generates nitrogen oxides that can impact ground-level ozone, irritating the lungs and airways.
  • Changing weather patterns alter barometric pressure, which can trigger sinus problems and make breathing harder if you have asthma.
Dramatic lightning bolt illuminates a dark stormy sky with thick clouds. A silhouette of trees is visible below. The scene captures the powerful and dynamic energy of the storm.

How to manage environmental allergy triggers

The key to managing asthma and allergy symptoms during any season is knowing your triggers. Pollen might bother you a bit, or it can make you feel miserable. You might find cold air ramps up your asthma symptoms.

Asthma and allergies are unique to each person. Here are some tips to help you manage environmental allergies:

  • Use an app or weather forecasting site. Keep an eye on potential weather changes that might affect you. Check the pollen count, mold spore count, air quality index, humidity, temperature, and changes in barometric pressure. Sign up for alerts via email or text.
  • Stay indoors and limit outdoor exercise when the pollen count is high or the air quality is poor.
  • Wear a mask when gardening or cutting grass. This can limit exposure to pollen, mold spores and air pollution.
  • Use a scarf to shield your mouth and nose in cold weather. The scarf warms and humidifies the air before you breathe it in, reducing shock to your airways.
  • Keep humidity levels in your home steady. Air conditioning, dehumidifiers or humidifiers can help keep your airways from becoming inflamed.
  • Take all your asthma medicines as prescribed. These help you control your asthma daily and during an asthma attack. Follow your Asthma Action Plan and your doctor’s recommendation for treatment.
  • Use air filters to remove allergens from indoor environments and reduce asthma triggers. Pollen can come inside due to open doors and windows. Mold, animal dander (pet allergens) and dust mites, and mold are also common indoor allergens.

Managing hay fever (Allergic Rhinitis) Symptoms

Hay fever, more commonly known as allergic rhinitis, is a seasonal allergy. It is caused by exposure to allergens, including pollen from trees, grasses, weeds and other plants. Hay fever symptoms include runny nose, nasal congestion, sore throat, itchy eyes, headache, fatigue and postnasal drip. Severe symptoms can impact asthma, causing coughing, wheezing and shortness of breath.

If you think you have hay fever symptoms, work with your doctor to identify your triggers. They may vary from person to person. Your doctor may recommend allergy testing. Develop a treatment plan based on the results.

A collage showcasing different weather patterns: clear blue skies, fluffy clouds, a bright sunburst, lightning in a dark sky, and a vibrant orange sunset. Each section represents a different atmospheric condition.

How does weather impact asthma symptoms?

Weather can significantly impact people with asthma. First it is important to define what is asthma. Asthma is a chronic condition that causes inflammation and your airways to tighten, usually in response to a trigger. Sudden changes in the weather and extreme heat or cold can trigger asthma symptoms. So can windy conditions that spread pollen and mold spores. Asthma symptoms include coughing, wheezing, shortness of breath and chest tightness.

If outdoor conditions affect your asthma, it’s essential to monitor the weather daily. Take precautions based off the forecast, pollen count and air quality alerts. Use your daily controller inhaler as prescribed and a quick-relief inhaler when symptoms arise. For allergic asthma, take prescription or over-the-counter allergy medicines to treat allergies.

When is pollen season and how does it impact allergies?

For most people, pollen season is in the springtime and the fall. Most trees, grasses and flowers bloom in the spring and release pollen. In the fall, ragweed pollen emerges. But depending on where you live, pollen may be present year-round.

Here’s a look at the four seasons and the weather factors that can contribute to asthma and allergies:

A child stands in a lush field of yellow flowers, looking upward. The vibrant blossoms surround them, creating a sea of yellow against the green stems. The child wears a patterned shirt, adding a contrast to the bright floral background.

Spring

When most people think of allergy season, they think of springtime when plants come to life and pollen and mold invades the air. Warm weather and rainfall in spring aids plant growth. Showers may offer people with allergies and asthma a break. Moisture weighs down the pollen, keeping it on the ground. Depending on where you live, tree pollen levels are highest in April and May – earlier in southern and southwestern states. Grass pollen levels start to rise in late spring and early summer.

A woman and a man walking with bicycles through a sunlit, wooded area. The woman, in a pink tank top, and the man, in a striped shirt, are smiling at each other. Sunlight filters through the trees, casting dappled shadows on the ground.

Summer

Grass pollen is at its peak from late May through early July, when dry, breezy conditions spread pollen. Thunderstorms with heavy winds can spread allergens further – especially small particles of pollen. These are inhaled more easily and can go deeper into the lungs.

A family of four is walking in a grassy field towards a black SUV with an open trunk, carrying camping gear. The sky is blue with scattered clouds, and a line of trees is visible in the background.

Fall

Ragweed season begins in late summer, peaking in September and typically ending by the first frost. One of the most potent allergens, ragweed makes life miserable for many with itchy eyes and sinus symptoms. It can also trigger asthma. Mild temperatures, reduced humidity, and breezy conditions create the ideal environment for ragweed plants to release pollen.

A couple ice skating on a snowy outdoor rink surrounded by pine trees. They are holding hands and smiling, wearing winter coats and knit hats. Other skaters are in the background, enjoying the winter setting.

Winter

People in the Southwestern United States, Mexico and Japan may experience winter allergies to the Ashe Juniper tree – commonly referred to as mountain cedar. This tree releases its pollen every year from December to February. For most other people living in areas with cold weather, winter is a welcome outdoor respite from allergies.

However, keep an eye on weather patterns. A mild winter can cause plants and trees to pollinate early – especially if there’s a lot of rain – leading to an early start to spring allergy season. Moisture from snowmelt in late winter can cause trees to produce more pollen when they bloom.

A woman outdoors sneezing into a tissue surrounded by a park with autumn leaves. She is wearing a light-colored coat and looking upwards. Trees with yellowish-green foliage are in the background.

How does climate change impact seasonal allergies?

Many scientists and doctors think climate change is a factor behind extreme pollen seasons and a rise in seasonal allergies. Fueled by mild winters and higher temperatures, plants are blooming earlier and for longer periods of time in many parts of the country. The extended growing season means higher levels of pollen in the air and worsened allergies for many people.

Many people with allergies experience worse seasonal symptoms when early spring weather fluctuates between warm and cold. This is called the “priming effect.” When there’s an early warm spell, trees and grass release a first round of pollen. The resulting allergic reaction “primes” a person’s immune system for more severe pollen reactions later in the spring.

During longer allergy seasons with high pollen counts, allergy patients may find they need to use more medication to manage symptoms. Talk with your doctor about whether you should adjust your allergy management plan or medication schedule. Your doctor can also discuss whether allergen immunotherapy for pollen is right for you.