Washington Allergy Season: Peak, Timing, and Symptoms

Written by Drew Wood
Updated: April 20, 2023
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Washington state has a diverse landscape that includes mountains, coast, and lush northern rainforests. Along with the beauty of this landscape comes a number of different causes of allergies in Washington state. These include pollen from trees, grasses, and weeds, as well as mold and dust mites. People who are allergic can suffer from symptoms like sneezing, congestion, and itchy eyes. This can make daily life miserable during allergy season.

In this article, we’ll cover the main causes of allergies in Washington and what time of year they are bad. We’ll look at allergy testing, over-the-counter treatments, and how to recognize and treat allergies in your pets. Whether you live in Washington or are planning to visit, we’ve got you and your fur babies covered.

What are Allergies?

Allergies result from the immune system overreacting to allergens like pollen, pet dander, and foods. The body releases chemicals such as histamine to fight them off. This creates symptoms like rashes, sneezing, itching, congestion, and throat constriction. If not treated, allergies can cause problems like sinusitis, which creates sinus pressure, headaches, and facial pain. It can also cause fluid buildup in the ears leading to ear infections, along with sleep problems and skin rashes. In the most severe cases, allergies can cause anaphylaxis. This is a life-threatening condition that causes problems breathing and a drop in blood pressure, which can be deadly.

Over time, allergies can get better or worse on their own. Children, for example, sometimes outgrow allergies as they are exposed to them over time. Other times, a person may develop a new allergy. Additionally, an existing allergy can get worse, especially at times when allergens are especially strong.

Protecting oneself from allergies involves avoiding allergens and treating the symptoms with medicines like antihistamines. Allergy testing can reveal what specifically you’re allergic to so that you can avoid it. An allergist can also suggest alternatives for treating allergies. These may include methods that involve gradual limited exposure to allergens to help your body develop resistance to them.

Woman with allergy symptoms

Allergies result from the immune system overreacting to allergens like pollen, pet dander, and foods.


When is the Worst Time for Allergies in Washington State?

A diverse environment and abundant plant life make allergies in Washington more challenging than in some other areas of the country. Western Washington has a mild, wet climate with lush evergreen forests of Douglas fir, western red cedar, and Sitka spruce. The eastern part of the state is more mountainous and arid. The vegetation there includes sagebrush steppe and ponderosa pine forest. Washington’s flora also includes deciduous trees like maple, ash, and cottonwood as well as many wildflowers and grasses.

Here are some of the main allergies in Washington state you may have to combat:

  • Tree pollen is most prevalent in the spring, with peak season usually occurring in April and May. Common allergens include alder, birch, cedar, and juniper.
  • Grass pollen is most prevalent in the summer, with peak season usually occurring in June and July. Common allergens include timothy grass, Kentucky bluegrass, and orchard grass.
  • Weed pollen is most prevalent in the fall, with peak season usually occurring in August and September. Common allergens include ragweed, goldenrod, and sagebrush.
  • Mold is present throughout the year but can be more prevalent in the fall and winter. During these seasons, the weather is cooler and more humid.
  • Dust mites are present all year, but their allergens can be more prevalent in indoor environments.

Note that predicting allergy season is not an exact science. Timing the likely peak season of allergies in Washington State can depend on weather conditions and other factors.

Nisqually River in Washington State

Knowing how to manage your allergies can help you enjoy outdoor activities in Washington.


What is Pollen Count?

Pollen count is a measure of the amount of pollen in the air. It is calculated as the number of pollen grains per cubic meter of air. A high pollen count might be over 120 grains/m3. This information is very useful to help plan activities to avoid times of high pollen concentrations in the air. They might also decide to take allergy medication proactively to head off allergy attacks.

During allergy season, local news channels, meteorological offices, and websites report the area’s pollen count on a daily basis. A lot of different factors like wind speed, rain, and temperature fluctuations can all affect pollen count. If you have severe allergies, pollen levels are something to take note of on a daily basis.

Allergy Season

On heavy pollen days, it can be difficult to work, study, or even enjoy a simple walk outside.

©Chad Robertson Media/Shutterstock.com

How Can You Be Tested for Allergies?

If you are experiencing allergy symptoms, your doctor might recommend testing you for allergies. This is particularly important if your symptoms are severe and you’re having trouble controlling them with over-the-counter medications. Two of the main ways allergists test for allergies are skin tests and blood tests.

In a skin prick test, a small amount of allergen is rubbed on the skin of the back or forearm. The skin is gently pricked to get the allergen under the skin. An allergist will probably do multiple such tests at the same time using some common allergens in your area. Any reaction, like a raised, red, itchy welt at the test site, will determine what you are allergic to. If none of the tested allergens cause a reaction, then they may repeat the test with other allergens.

Another way to test for allergens is with a blood test, such as the RAST (Radioallergosorbent Test) or ImmunoCAP test. These tests measure the level of specific antibodies in the blood that are produced in response to an allergen. Blood tests are actually less accurate than skin tests, but they are sometimes used with people who cannot take a skin test because of certain medications. They can also confirm the results of an ambiguous skin test.

Allergy Test

An allergist may put a small drop of different allergens on the skin of your arms or back to find out what you are allergic to.


Allergy Symptoms Without Allergies

Sometimes an allergy test turns up negative, yet you still have congestion, sneezing, and a runny nose. An allergist might check you for sensitivity to less-common allergens, but if those also turn up negative it’s possible you have a condition known as non-allergenic rhinitis.

In non-allergenic rhinitis, you can have the symptoms of allergies for many different reasons, such as viral infections, irritants like smoke, cologne, cleaning supplies, hormonal changes; or some kinds of medication. Another cause of it can be problems in the structure of your nasal passages, like a deviated septum, that contributes to chronic inflammation. Structural issues may be correctable with surgery. Otherwise, non-allergenic rhinitis is treated like an allergy: with antihistamines and decongestants and avoiding things that seem to be triggering.


Non-allergenic rhinitis causes many of the same symptoms of allergies and is often treated in similar ways.


Avoiding Allergens

The best way to prevent allergies is to avoid exposure to allergens, but of course, they are everywhere and impossible to escape completely. If you can identify exactly what you are allergic to, you might be able to remove it from your environment. A person particularly susceptible to the typical kinds of allergies in Washington state might have to make the unfortunate decision to move a geographic area that does not have that species or has a shorter allergy season.

Buying unscented detergents, deodorants, and tissues and abstaining from perfumes and colognes would be a good start. Obviously, if a particular food bothers you, then don’t eat it and don’t keep it in your house if that’s an option. Do your research and find workable alternatives. If particular trees, shrubs, or other outdoor plants bother you, you can remove them from your property and replace them with allergy-friendly species.

During allergy season, keeping your windows closed, using air conditioning and an air purifier, showering and changing your clothes after spending extended time outside, and washing your bedding and towels regularly in hot water are all good ways to reduce allergens in your living space. Regularly dusting your house with a microstatic cloth and vacuuming your floors might aggravate your symptoms at first by stirring up dust, but in the long run, doing so regularly will reduce the number of allergens in your home and make your life a bit easier.

dust mite

Dust mites are a common source of allergies. You can help combat them by regularly washing and drying your bedding, towels, and curtains.


Medical Treatments for Allergies

Medically, you can treat your allergy symptoms at home with over-the-counter antihistamines, decongestants, nasal sprays, eye drops, or anti-itch creams. Even in the absence of symptoms, allergy sufferers might mark their calendars for when allergy season seems to particularly affect them each year and take some of these medications proactively.

In case of severe allergies, you might want to consider immunotherapy, in which you will be exposed to small amounts of allergens over time to help your body recognize them and respond appropriately to them. In the worst-case scenarios, a severely allergic person may be prescribed an epi-pen to inject themselves or be injected by a bystander when exposed to a life-threatening allergy, such as a particular food or bee sting.

Allergy sufferer

Taking medications proactively during allergy season is one way to manage the challenges of high pollen counts.


Best Over-The-Counter Allergy Treatments

When it comes to managing allergies, it is worth considering the option of using generic over-the-counter treatments. They can be just as effective as brand-name products. In fact, many of the best-known brand-name allergy treatments have generic counterparts that are available at a more affordable price point. To help you compare, below are links to generic equivalents of four popular brand-name treatments.

Amazon Basic Care Loratadine Antihistamine
  • Long-lasting relief from allergy symptoms
  • Non-drowsy formula
  • Active ingredient is the antihistamine Loratadine (10 mg)
  • 24-hour allergy relief
Check Amazon
ValuMeds 24-Hour Allergy Medicine
  • 24-hour allergy relief
  • Works for pollen, hay fever, dry eyes, itchy eyes
  • Main ingredient is Cetirizine HCl
Check Amazon
ValuMeds Antihistamine, Diphenhydramine HCl 25 mg
  • 600 tablets
  • Active ingredient: Diphenhydramine HCl 25 mg
  • Suitable for Children and Adults
  • Relieves Itchy Eyes, Runny Nose, Sneezing

Check Amazon
HealthCareAisle Allergy Relief - Fexofenadine Hydrochloride
  • Active ingredient: Fexofenadine Hydrochloride
  • 90 tablets of 180 mg
  • Non-Drowsy
  • 24-Hour Allergy Relief

Check Amazon

Before self-treating for allergies, it’s best to consult with your doctor, nurse practitioner, or pharmacist to make sure any OTC meds you are contemplating will not interfere with any prescription medications you may be taking. A combination of methods may be necessary to control all your symptoms, but you also don’t want to overdo it. Taking an allergy medicine that makes you sleepy all day may be just as disruptive to your life as putting up with milder allergy symptoms.

Tylenol in pharmacy

Consult with a healthcare professional to make sure what you take does not interact badly with other prescription or OTC meds you are taking.


Allergies in Washington State Affect Pets, Too

Pets — particularly mammals — develop allergies just as people do. Allergy symptoms look different depending on the pet and the allergy. In general, look for your pet to bite, scratch, or lick at its skin or lick and chew its paws. Cats might groom themselves excessively, sometimes stripping all the fur off their bellies and inner legs. Hair loss, red and irritated skin, and breathing problems are all possible signs of allergies.

Types of Allergy Causes

Pets are most commonly allergic to certain types of foods, things in their environment, or reactions to flea bites. Some pets are allergic to protein from beef, chicken, fish, dairy products, or some preservatives and additives. Lamb and rice dog foods are sometimes good in these cases.

Environmental allergies can include pollen, mold, dust mites, and more. You might try to notice if your animal’s allergies get worse when you do things like dusting, sweeping, or changing sheets, which all stir up allergens. Immunotherapy, changes in the animal’s environment, or medications may be necessary.

Flea allergy dermatitis is a reaction to flea bites that causes intense itching. Washing the animal with flea-killing shampoo is the first step. However, you’ll need to get them on regular flea treatments which can be administered as an easy monthly pill or oil that can be applied to a cat or dog’s skin between the shoulder blades so that it soaks into the skin. Remember an animal with fleas likely has brought them into the house, so you may need to have your house treated if you have an infestation. Even when the fleas are cleared up, your animal may still need treatment for the irritated skin they have caused. Fleas are bad news for pets — you’ll want to get a handle on them right away if they show up.

Cat licking its paws

Excessive grooming, especially licking or biting the paws, can be signs of an allergic reaction in your dog or cat.

©Fayzulin Serg/Shutterstock.com

Can Pets Take Human Allergy Medicine?

Treating pets with human allergy medication should always be done under the guidance and supervision of a veterinarian. This is because pets may have different reactions to human medications. Some medications that are safe for humans can be toxic to pets. Certain human antihistamines, such as diphenhydramine, can be safe for pets. But you must adjust the dosage and frequency according to the pet’s weight, breed, and health condition. Moreover, some medicines that are safe for dogs are toxic to cats, so getting expert advice is a must.

It is also important to note that not all antihistamines will work the same way in pets as they do in humans. Human allergy medications such as nasal sprays, corticosteroids, and immunomodulators can give pets serious negative side effects.

It is always best to consult with a veterinarian before giving any medications to your pet, as they will be able to recommend the best treatment option for your pet’s specific condition and provide guidance on the correct dosage and frequency of medication.

spay a dog at petsmart

A veterinarian is a dog’s best friend when it comes to allergies. Ask your vet to help diagnose and devise the best treatment plan for your pet.


The photo featured at the top of this post is © iStock.com/RomanKhomlyak

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About the Author

Drew Wood is a writer at A-Z Animals focusing on mammals, geography, and world cultures. Drew has worked in research and writing for over 20 years and holds a Masters in Foreign Affairs (1992) and a Doctorate in Religion (2009). A resident of Nebraska, Drew enjoys Brazilian jiu-jitsu, movies, and being an emotional support human to four dogs.

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