Allergies In Phoenix: Everything To Know

Written by Hannah Ward
Published: February 21, 2023
© Deep Desert Photography/
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Many people suffer from seasonal allergies, and the symptoms can range from mildly annoying to severe enough to change your lifestyle during the allergy season. Phoenix, AZ, is known for having a long allergy season due to its climate. However, regardless of whether you live there, work there, or are just passing through, you probably want to know more about their allergy season. Read on to discover everything you need to know about allergies in Phoenix, including which plants are common allergens and how to treat your allergy symptoms.

When Is Allergy Season in Phoenix?

Grass, Bermuda, Lawn, Abstract, Backgrounds
The primary grass allergen in Phoenix is Bermuda grass.

© Consaul

Many assume Arizona has very few allergy triggers due to its desert landscape. In the past, people were commonly recommended to move to the desert to escape their allergies. However, due to it’s warm, dry climate and year-round growing season, the allergy season in Phoenix lasts virtually all year. The mild winter and little rainfall means that there is very little relief from allergies at all. Despite this, Phoenix has a low overall ranking amongst 2022’s allergy list by the Asthma and Allergy Foundation of America, ranking at 92 with only a marginal difference between spring (97) and fall (90).

How Do Plants Cause Allergies?

Have you ever wondered why you have allergies or why plants trigger them? Allergies are actually caused by an immune response in your body. The body identifies certain substances (known as allergens) as potential threats even though they are usually completely harmless. When this happens the body reacts and attempts to destroy the threat. This then results in the occurrence of the common allergy symptoms — a runny nose, sneezing, watery eyes, and a sore or itchy throat.

Although there are many other types of allergies — such as food, pet hair, and mold — plant allergies are some of the most common. But it’s not the plants themselves but the pollen that they produce. Pollen is the microscopic grains produced by the male parts of plants and trees. It is mainly transported by the wind and animals such as birds and insects to pollinate the female plants. However, when these tiny fragments enter our airways, the immune response is triggered in people allergic to them.

Plants That Cause Allergies in Phoenix

Mulberry tree in steppe
Many types of trees, including mulberry trees, can trigger allergies in Phoenix.

©Roman Kutsekon/

Although you now know how plants cause allergies, it’s essential to understand that not every plant is an allergen. Also, even with a plant allergy, you might not be allergic to every plant. Three main groups cause allergies — trees, weeds, and grass. Let’s look at them and identify the primary triggers of allergies in Phoenix.


Trees are active pollinators, and many different types can trigger allergies in Phoenix. The most common are ash, cottonwood, mesquite, mulberry, and juniper trees. Mesquite and mulberry are deciduous trees that produce large pollinate in the spring between March and April. However, junipers are coniferous trees, and one of the major allergens in Phoenix is the Ashe juniper — also known as mountain cedar — which typically pollinates during the winter months.


Regarding grasses, the primary allergen in Phoenix is Bermuda grass (Cynodon dactylon). Bermuda grass, also known as crabgrass, is an introduced species to the U.S. It is fast-growing and challenging, recovering quickly if damaged. These qualities also mean it can survive in conditions other species struggle with — particularly in hot, dry areas such as Arizona.


Although several weeds and shrubs trigger allergies, the most prolific in Phoenix is ragweed (Ambrosia sp.). Ragweed can reach up to 3.5 feet high and produce an astonishing one billion pollen particles from a single plant in one year. However, another reason it triggers allergy sufferers is that it tends to have two pollinating seasons in Arizona — spring and fall.

Aside from ragweed, the Russian thistle is another weed that produces a lot of pollen. Russian thistle (Kali tragus) is known as tumbleweed and pollinates between May and November. As well as causing the typical allergy symptoms, contact with it can also cause a skin rash.

How to Treat Your Allergy Symptoms

If you do suffer from allergies in Phoenix, then there are a few steps that you can take to help ease your symptoms. The most effective method is to avoid coming into contact with pollen. Although this may seem impossible, you can limit your exposure by making a few changes.

First, check the pollen count for your area and avoid going outdoors when the pollen count is high. Plus, keeping your windows and doors closed as much as possible will prevent a lot of pollen from entering your home. Also, avoid doing outside chores such as mowing the lawn or weeding. This is because these can stir up pollen and make your symptoms worse. If you spend any length of time outdoors, it’s advisable to change your clothes as soon as you return indoors, as pollen can cling to fabric. Another good way to keep your home free from particles that can aggravate your allergies is to use a dehumidifier or a powerful air filter, such as a HEPA filter.

If you’re still struggling with your symptoms, then it may be time to look at treating them. First of all, if your symptoms are severe, you should speak to your doctor. Your doctor can offer you specific advise and will be able to provide a variety of treatment options. However, the most common allergy treatments are over-the-counter antihistamine tablets and corticosteroid nasal sprays.

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Robber's Roost Peak has a large cave. That cave became a hideout for many criminals over the years because it was almost impossible to reach thanks to the sheer mountain face.
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About the Author

I have been writing professionally for several years with a focus on animals and wildlife. I love spending time in the outdoors and when not writing I can be found on the farm surrounded by horses, dogs, sheep, and pigs.

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