Washington State is known for its incredible natural landscape, glaciated volcanoes, lush rainforests and the scenic Pacific coastline.

For people with allergies, however, the state’s diverse landscape and vegetation can also mean exposure to different allergens throughout much of the year, which can affect day-to-day living.

If you are an allergy sufferer in the Evergreen State and are tired of allergies constantly getting in the way of enjoying where you live, Quello Allergy Drops can help.  

Quello’s allergy drop treatment, including access to an expert care team, is available to allergy sufferers in Washington, no matter where you live.

What Are the Common Allergens in  Washington State?

An allergen is a substance that triggers an allergic reaction, leading to symptoms such as a runny nose, itchy eyes or nose, sneezing or nasal congestion. (1)

Some of the most common allergens in Washington State include: (2,3)

• Tree Pollens: Pollen from cedars (especially red cedars), juniper, alder, willow, oak, birch, elm, pine, sycamore

• Grass Pollens: Pollen from Bermuda, Rye, Orchard, Timothy, Johnson, Sweet Vernal and Redtop

• Weed Pollen: Pollen from Russian thistle, fireweed and Scotch broom.

• Mold Spores

• Dust mite
  

When is Allergy Season in Washington State?

Allergy season in Washington State can last year-round, although winter may be milder for people with pollen allergies. Tree pollens usually appear first in spring, followed by grass pollens in late spring and early summer, and finally weed pollen in late summer and fall. (4)

In Washington State, pollen season may be longer and start sooner. (2) According to the Washington State Department of Health, pollen season in the state now starts about 20 days earlier and lasts almost a month longer than it did 30 years ago.

Washington State Allergy Calendar By Season

Allergy season in Washington may vary, as different trees, grasses, weeds, and other allergens become more active at different times of the year.

Spring Allergy Season in Washington State

Spring allergy season in Washington generally runs from February through May, with tree pollen dominating earlier in the spring and grass pollen becoming more important toward late spring.

In Washington State, April is often a peak month for spring allergies due to high tree pollen levels.

Tree pollens that may trigger spring allergies in Washington State include: (5, 6)

• Western Red Cedar

• Douglas Fir

• Alder

• Birch

• Junipers

• Oak

• Black cottonwood (pollen, not the white fluff)

• Bigleaf maple

Some grass pollens from Bermuda, Orchard, Rye grass, Fescue and Timothy grass may also trigger allergies from late spring (May) into early summer (June).

In addition, Scotch broom, a weed, also contributes to spring allergies. It typically blooms from March or April through June in Washington. (7)

Summer Allergy Season in Washington State

Generally, Summer allergy season in Washington State typically lasts from May through July and is dominated by grass pollen.

Common grasses that release pollen which can trigger allergy symptoms include: (6)

• Blue Kentucky

• Canarygrass

• Meadow Fescue

• Redtop

• Timothy

• Wheatgrass

• Bermuda

• Salt grass

• Rye

Some weeds, such as ragweed, sagebrush, and mugwort, may start releasing pollen in late summer, which can also trigger allergies.

Fall Allergy Season in Washington State

Fall allergy season in Washington State typically starts in mid-August and lasts till late October or till the first hard frost.

The main culprits of fall allergies in Washington State are weeds such as;

• Sagebrush (Eastern Washington State)

• Russian Thistle (Tumbleweed)--Eastern and central Washington State

• Ragweed-Less dominant

• Redroot pigweed

• English Plantain

• Nettles

Winter Allergy Season in Washington State

Winter in Washington can vary considerably depending on where you live, which can influence exposure to seasonal allergens. In general, outdoor pollen levels are lower during winter than during spring, summer, and fall.

In Western Washington, winters are typically mild, wet, and cloudy, especially around Seattle, Tacoma, and Olympia. (8) While outdoor pollen exposure is generally lower in winter, indoor allergens such as mold, dust mites, and pet dander may still trigger symptoms. 

In Eastern Washington, winters are generally colder and snowier, so outdoor pollen activity is typically limited during this period. (9) However, indoor allergens can still cause symptoms year-round.

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Washington State Allergy by Region

The allergy landscape in Washington varies considerably from west to east. Western regions are influenced by the Pacific Northwest, while eastern areas are influenced by the Intermountain & High Desert. (10)  As a result, allergy triggers and pollen timing can differ depending on where you live.

Allergy season in Western Washington (Seattle, Tacoma, Olympia, Everett)

Cities in Western Washington, such as Seattle, Tacoma, and Olympia, have lush vegetation and may experience higher pollen levels during the spring and summer.

Tree pollen is a major seasonal allergy trigger in Western Washington, with trees such as birch, cedar, and alder contributing to pollen exposure. In Seattle, birch pollen is the third most abundant pollen type, and scientists predict that birch pollen levels in Western Washington could be eight times higher by the end of the century. (2)

Other common pollen triggers in Western Washington include maple, hazelnut, alder, oak, elm and cedar. (3)

Allergy season in Eastern Washington (Spokane, Walla Walla, Pullman)

Allergy sufferers in Eastern Washington, especially in places like Spokane, can experience particularly challenging allergy seasons. Eastern Washington is characterized by arid high desert, sagebrush, and pine forests, which can contribute to seasonal pollen exposure. (10) In addition, the region’s dry, windy conditions can help light pollen grains travel farther and remain airborne longer, potentially worsening seasonal allergy symptoms.

Spokane is currently ranked ninth among the 100 most challenging U.S. metro areas for pollen allergies in AAFA’s 2026 Allergy Capitals report. It also has a worse-than-average pollen count.

Common pollens that may trigger allergies in this Eastern Washington include sycamore, cedar, alder, cottonwood, mulberry and pine. (3)

Allergy season in Central Washington

Central Washington has a semi-arid, continental climate, with hot, dry summers, cold winters, and relatively little rainfall. (8, 11) These dry conditions, combined with the region’s grasslands, sagebrush, farmland, and orchards, can increase seasonal pollen exposure, particularly in spring and summer. Dry, windy weather may also keep pollen airborne and help it travel farther.

Tips for Surviving Washington Allergy Season

Here are some tips for managing allergies in Washington, regardless of the season or where you live, based on recommendations from the Washington State Department of Health. (2)

• Monitor local pollen levels before heading outdoors. Pollen counts and seasonal charts for Seattle and Eastern Washington are available through the Northwest Allergy & Asthma Center.
  

• Consider staying indoors during peak pollen times.

• Always shower after being outdoors to remove pollen from your hair, skin, and the clothes you wore outside.

• Use air purifiers and change the filters regularly.  Also, change your AC unit filter regularly, and consider a higher MERV rating (which measures an air filter's ability to capture smaller particles) to remove more pollen.

• When possible, keep windows closed during peak allergy season, or consider installing air conditioning, especially during the hot summer months.

• Vacuum your carpets and wipe down dusty surfaces to reduce indoor allergy triggers from dust mites.

• Consider using allergy medications for relief when needed.

Allergy Treatment in Washington

Some available allergy treatments that may help you manage your symptoms include:

1. Over-the-Counter Allergy Medications

Common over-the-counter (OTC) allergy medications, including Benadryl, Claritin, Allegra, and Zyrtec, can relieve allergy symptoms such as congestion, runny nose, and sneezing.

OTC allergy medications typically take a few days to a few weeks to work. Some OTC allergy medications are formulated for short-term use only.

For example, nasal decongestants should not be taken for more than 3 days, or your symptoms may worsen.

Wondering how long OTC allergy medications take to work?  Read: How Long Does Allergy Medicine Take to Work?

2. Prescription Medications

If OTC allergy medication doesn’t help or your symptoms affect your daily activities, your medical provider may recommend prescription allergy medications like steroids, mast cell stabilizers, or leukotriene modifiers.

3. Allergy Shots (Subcutaneous Immunotherapy)

Allergy immunotherapy, including allergy shots and certain sublingual treatments, may provide longer-lasting symptom relief by reducing sensitivity to specific allergens, unlike OTC or prescription medications that mainly control symptoms while you take them.  (12)

An allergy shot is a form of allergy immunotherapy that involves injecting a small dose of allergens just under the skin of your arm or thigh, with the dose gradually increasing over time.

These shots help your body develop a tolerance to the allergen's effects and, over time, can even eliminate your symptoms.

4. Allergy Drops (Sublingual Immunotherapy

Allergy drops work just like allergy shots. However, instead of getting needled at a doctor’s office, you’ll simply take your customized allergy drops at home by placing a few drops under your tongue each day.

Like allergy shots, allergy drops expose your immune system to your specific triggers, gradually desensitizing your body’s response to allergens and easing allergy symptoms.

Overcome Year-Round Allergies in Washington State with Quello Allergy Drops

If you live in Washington State and have persistent, year-round allergies, Quello Allergy drops can provide long-term relief.

Quello Allergy drops are a form of Allergen immunotherapy formulated to retrain your immune system to respond better to allergies.

Our Allergy drops do not just target symptoms; they treat the root cause of allergies, so you can spend more time enjoying Texas and less time managing sneezing, congestion, or itchy eyes.

Ready to get started? Schedule a free consultation with one of our allergy specialists.

Suggested Reading

Traveling or moving to another state? Learn when allergy season starts, which allergens to watch for, and how to find relief:

• A Survival Guide to Allergy Season in Colorado: Find out when Colorado allergies peak and how to manage symptoms during your visit or move.

• A Survival Guide to Texas Allergy Season: Learn common Texas allergy triggers, seasonal timing, and treatment options to help you prepare.

• A Survival Guide to Florida Allergy Season: Learn what causes allergies in Florida and how to reduce exposure and manage symptoms year-round.