Oregon Allergy Season: Peak, Timing, and Symptoms

Written by Jennifer Gaeng
Updated: January 27, 2023
© Eric Backman/Shutterstock.com
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Even though Oregon is a gorgeous state, those who suffer from seasonal allergies should be aware that the state maintains generally consistent temperatures throughout the year. Due to its extremely high pollen counts in comparison to the rest of the country, Oregon is consistently ranked as one of the worst states for allergies.

But what can people in Oregon do about the terrible seasonal allergy seasons? What kinds of pollen allergies are most prevalent, if any? Find out the answer and how to control your allergy symptoms by reading this article.

When Is Allergy Season In Oregon?

Clackamas river
Oregon has mild winters and is ideal for plant life. However, this means that allergy seasons tend to last longer.

©Victoria Ditkovsky/Shutterstock.com

Oregon’s mild winters, sunny summers, and temperate autumns make it an ideal place for plant life. However, this also means that residents in Oregon will have to deal with outdoor airborne allergies year-round, unlike those in many other areas when winter might provide some relief.

Peak Timing

The prevalence of seasonal allergies in Oregon is high, with symptoms often worsening between late spring and early summer. During peak season, the south valley region experiences some of the highest pollen levels in the country. The months of May and June are ideal for pollinating grasses. In the next sections, we’ll examine which pollens and plants reach their peak at different times of the year.

Which Plants Cause Allergies In Oregon?

Bluebunch Wheatgrass
Wheat grasses thrive in Oregon and are a common culprit for allergy symptoms.

©T9500 / public domain – License


There is more tree pollen in Oregon than in any other state. However, tree allergies in Oregon don’t really begin until spring. Late in the month of February, alder and birch trees will begin spreading their pollen. March and April will witness the addition of ash, beech, cottonwood, locust, maple, oak, pecan, and sycamore trees.


Grass pollen levels in Oregon are among the highest in the United States. Oregon’s grass allergy season often begins in the summer. The primary offenders are the grasses of Bermuda, wheat, fescue, and orchard grass, with pollen concentrations peaking in the month of June.


Oregon’s weed allergy season often begins in the autumn. The most common offenders are plantain weed and ragweed. Usually, the beginning of weed allergy season occurs in late August and continues until the first frost.


Unlike in some other areas, allergy sufferers in Oregon don’t get much of a break during the winter. Cypress, hazelnut, juniper, and spruce trees all start releasing pollen in December, which marks the beginning of tree allergy season.

Common Allergy Symptoms

Allergy sufferer
Allergy sufferers tend to cough and sneeze as a part of their symptoms.


Because of Oregon’s moderate and wet environment, inhabitants are exposed to a wide variety of grass, tree, and weed pollens.

The following allergy symptoms are common in Oregon:

  • Cough
  • Headaches
  • Hives
  • Itchy eyes
  • Itchy throat
  • Severe asthma symptoms
  • Sneezing
  • Stuffy and/or runny nose
  • Watery eyes

As usual, everyone reacts differently, but allergies typically manifest themselves in some combination of these ways.

Most Effective Allergy Treatments

At any one moment, the air around areas where people suffer from seasonal allergies will contain a wide variety of pollen. Since this is the case, it may be challenging to pinpoint the exact allergen(s) that are triggering your reactions. Fortunately, there are a variety of treatments available to you to help you manage your symptoms so that you can take full advantage of the pleasant spring and summer months.

Keep Exposure Minimal

Avoiding your allergies is highly recommended if you want to avoid using medications. Keeping your home tidy, closing your windows, taking frequent showers after being outside, monitoring the pollen forecast, and maintaining your yard are all possible solutions.

OTC Allergy Medications

Medications for allergies are available if limiting your exposure proves unsuccessful. Numerous over-the-counter and prescription medications are available to treat allergy symptoms, including antihistamines, eye drops, decongestants, and nasal sprays.

Consult a Physician

When over-the-counter remedies for allergies fail to alleviate your symptoms, it’s time to see a doctor. They might recommend a stronger medication or send you to an allergist for testing. After reviewing your test findings, an allergist may suggest immunotherapy as a treatment option.


Allergies to things like grass pollen, dust mites, and bee venom can be avoided with the help of immunotherapy. In immunotherapy, the allergen (material to which a person is hypersensitive) is administered to the patient in escalating amounts.

Almost all immunotherapy treatments are effective. An estimated 85% of individuals who underwent immunotherapy reported complete or substantial relief from their allergy problems. It has been proven that allergy drops are equally as helpful as allergy shots for those who suffer from allergies. And many patients report quicker improvement.

Click here to learn about all of the allergy seasons across the United States!

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About the Author

A substantial part of my life has been spent as a writer and artist, with great respect to observing nature with an analytical and metaphysical eye. Upon close investigation, the natural world exposes truths far beyond the obvious. For me, the source of all that we are is embodied in our planet; and the process of writing and creating art around this topic is an attempt to communicate its wonders.

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