There are plenty of allergens that can cause a variety of symptoms in those who are allergic to them. Pets, insects, mold, lots of foods – there are plenty to cause trouble. But seasonal allergies seem to be the most talked about. (Think of every commercial you’ve seen in the spring to promote an over-the-counter antihistamine.) So, what is at the root of all these seasonal allergies? Pollen.

What are pollen allergies?

A pollen allergy is when your body has an immune system reaction to a normally harmless substance. In this instance, that substance is pollen.

What is pollen?

In technical terms, it’s the male fertilizing agent of flowering plants, trees, grasses, and weeds.¹ In non-technical terms, it’s the yellow powdery stuff that coats your car during spring.

The most common pollen allergy triggers are trees, grasses, and weeds. And due to pollen’s microscopic size, it travels easily through the air. This means that it’s not just the pollen in your backyard that could be causing symptoms. It also could be pollen that is traveling from miles away.

Pollen allergy causes

When you have a pollen allergy, your immune system mistakes pollen for a harmful substance and releases a chemical (histamine) to fight it off. The results of that reaction are symptoms like sneezing, runny nose, watery eyes, and congestion.

Learn more about some of the most common culprits causing pollen allergies, also referred to as hay fever.

Common tree pollen allergy triggers

Trees are usually the first plants to release significant pollen as temperatures start to rise. Tree pollen is typically at its worst February through May for most of the United States, though it can start earlier for warmer regions.²Learn more about the specific tree pollens that might be in your area by clicking on the allergen fact sheets below.

Pecan and Hickory Tree

Common grass pollen allergy triggers

Grass pollen often overlaps with tree pollen in late spring and continues through the summer. Grass pollen is most common from April through July.² Learn more about the specific grass pollens that might be in your area by clicking on the allergen fact sheets below.

Common weed pollen allergy triggers

Weed pollen typically runs from August through October/November (depending on when the first frost occurs). The most significant weed allergen in the U.S. is ragweed.² It’s especially problematic because plants produce substantial amounts of pollen and it can travel far. Learn more about the specific weed pollens that might be in your area by clicking on the allergen fact sheets below.

Flower pollen

When talking about pollen allergies, especially spring allergies, many people often think about flowers. It makes sense, since one of the first signs of spring is the blooming of flowers. And flowers produce pollen. However, flower pollen is not a significant contributor to pollen allergies. It’s because of the size of the pollen. Flower pollen is often heavy, sticky, and meant to be carried by insects. So, unlike pollen from trees, grasses, or weeds, flower pollen doesn’t travel through the air and isn’t easily inhaled.³

Is climate change making my allergies worse?

The changing climate has resulted in more frost-free days, warmer air temperatures, and more carbon dioxide in the atmosphere. Those changes have resulted in higher pollen concentrations, as well as earlier and longer pollen seasons.⁴ Does this mean your allergies are worse? Not necessarily. But it does mean that it’s very likely the amount of pollen you are exposed to and the length of time you are exposed to it are increasing.⁴

Pollen allergy symptoms

So, how can you tell if you are allergic to pollen? Knowing if you’re allergic to pollen involves recognizing common symptoms such as:

Sneezing
Runny nose
Scratchy throat

Irritated eyes
Coughing

Pollen allergy diagnosis

Knowing that your symptoms can change from day to day depending on the season, weather, or wind doesn’t make finding relief any easier. But getting to the bottom of what’s causing symptoms (is it pollen?) is a great first step. A specific IgE blood test measures the amount of allergen-specific antibodies in your blood. Learn more about how to get an allergy test here.

How to get an allergy test

Get tested

How to deal with pollen allergies:

If you are diagnosed with a pollen allergy, here are some practical tips to help you minimize exposure to your triggers.⁵

Shower after working outside. Wash hair, eyes, and eyelashes.
Remove work clothes outdoors, place them in a bag, and carry them to the washing machine.
Consider taking your allergy medicines before going outdoors if directed by your healthcare provider.
Stay indoors when pollen counts are high for pollens you’re allergic to.
Have someone else do your yard work, or wear a microfiber facemask.
At home and when driving, keep windows closed, and when possible, use an air conditioner.
Use high-efficiency particulate air (HEPA) filters for furnace and vacuum cleaners.

Frequently asked questions about pollen allergies

How to get rid of pollen allergies?

If you are diagnosed with a pollen allergy, your healthcare provider will help you with a targeted exposure reduction plan. That means they’ll make sure you know exactly which allergens will trigger symptoms, will help you avoid or at least minimize those triggers, and will offer up treatment options. Those treatment options can range from over-the-counter allergy medications to immunotherapy (allergy shots).

Can pollen allergies cause sore throat?

Sneezing, coughing, irritated eyes, and a runny nose are some of the most common pollen allergy symptoms. A sore throat is typically a more common symptom of something viral (like a cold). However, allergies also can cause a sore throat. That’s most likely the result of postnasal drip, when discharge from your nose runs down the back of your throat.⁶

How long do pollen allergies last?

Allergy symptoms typically last as long as you are exposed to the allergen. Tree pollens are usually worse from late winter through spring. Grass pollen often overlaps with tree pollen in late spring and runs through summer. Weed pollen is typically worse late summer through fall.

Does rain help with pollen allergies?

Yes and no. Rain showers can help capture pollen grains in the air and pull them to the ground, reducing airborne pollen levels.⁷ However, in a heavy downpour, clumps of grass and weed pollen can be broken into smaller particles that remain airborne.⁷

References

Pollen Defined [Internet]. American Academy of Allergy, Asthma & Immunology; 2024 Jul 8 [cited 2025 Feb 9]. Available from: https://www.aaaai.org/tools-for-the-public/allergy,-asthma-immunology-glossary/pollen-defined.
Pollen Allergy [Internet]. Asthma and Allergy Foundation of America; 2024 Sep [cited 2026 Feb 9]. Available from: https://www.aafa.org/pollen-allergy.
Allergens: Pollen [Internet]. Johns Hopkins Medicine [cited 2026 Feb 9]. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/seasonal-allergies/allergens-pollen.
Pollen: Spring Pollen Season is Getting Longer and More Intense [Internet]. US Department of Health and Human Services; 2024 May 6 [cited 2026 Feb 9]. Available from: https://www.hhs.gov/climate-change-health-equity-environmental-justice/climate-change-health-equity/climate-health-outlook/pollen/index.html.
Discover the connection: Reduce Exposure to Your Allergic Triggers. Thermo Fisher Scientific Inc. 2018.
Thompson C. Four Common Allergens That Might be Causing Your Sore Throat [Internet]. Aspire Allergy & Sinus; 2022 Sep 29 [cited 2026 Feb 9]. Available from: https://www.aspireallergy.com/blog/sore-throat.
How Does Rain Affect Pollen Levels [Internet]. Asthma and Allergy Foundation of America; 2024 Jul 15 [cited 2026 Feb 9]. Available from: https://community.aafa.org/blog/how-does-rain-affect-pollen-levels.