Allergies In Houston: Everything To Know

Written by Hannah Ward
Published: February 16, 2023
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If you live in Houston then you likely already know that it has a long allergy season, and the reason for this is that there are different types of plants and pollen that trigger allergies at different times of the year. In this article we’ll discuss in detail which plants, trees, and even mold are common allergens and when they’re likely to trigger your allergies in Houston. We’ll also explain some of the most common ways that you can treat your symptoms during the year.

When is Allergy Season in Houston?

With its warm and humid climate, allergies are prevalent almost year round in Houston, with the allergy season beginning in January and running through to September. According to the Asthma and Allergy Foundation of America, Houston ranks 34 overall on the list of cities with the highest allergy levels during 2022. However, this jumps to 27 during the fall and drops to 44 during the spring — meaning that fall is the worst time for allergies.

Allergies are prevalent almost year round in Houston.

With its warm and humid climate, allergies are prevalent almost year round in Houston.

©Silvio Ligutti/

Plants that Cause Allergies in Houston (By Season)

Allergy symptoms occur when the body misidentifies a substance (allergen) as something that is harmful to it. When this happens a natural immune response occurs and the body creates antibodies to attack the allergen. This then causes the common symptoms associated with an allergy — running nose, watery eyes, and sneezing.

Although there are many different types of allergies — such as food, insect, and pet — pollen allergies are one of the most common. However, pollen isn’t just one blanket allergen as there are also different types of pollen that can trigger your allergies throughout the year. Let’s take a look at the common plants that causes allergies in Houston below.


We’ve already mentioned that the allergy season in Houston begins in January, and from January through spring it is the time for the tree pollen. There are a vast number of trees that are major allergens during this time, but box elder is the most significant. Box elder pollinates from January to May. Its pollen is so strong that people with allergies can even experience an itchy rash if it comes into contact with the skin. Aside from box elder, other trees that contribute to the tree pollen season are oak, birch, juniper, willow, elm, ash, hickory, and mulberry trees.

Box elder maple spring flowers

There are a vast number of trees that are major allergens in Houston’s springtime, but box elder is the most significant.



By the time the summer rolls around most of the trees have finished pollinating and it’s time to turn our attention to the grass pollen. Grass pollinates during the hotter months of the year. However, it tends to finish by the time the weather begins to cool during the fall months. The most significant allergens in Houston during the summer are rye grass, timothy, sweet vernal, winter bent, upland bent, and blue grass.

Sweet vernal grass is a summer allergen

The most significant allergens in Houston during the summer come from grasses such as sweet vernal.



Fall is the peak allergy season in Houston and the major trigger is ragweed. Ragweed pollen occurs from mid-August until the first frost. Ragweeds are plants in the aster family Asteraceae and one single plant can produce up to one billion grains of pollen. Therefore, it’s no surprise that you suffer a lot during the fall months. However, other allergens during fall are elm trees, curly dock, broom sedge, black medick, and mold.

Mold, in particular, is a significant problem in Houston as the humid climate is the perfect breeding ground for spores. The main spores that cause problems are Ascomycetes and Cladosporium. These are some of the most common indoor and outdoor molds.

The ragweed plant is a major allergen

One single ragweed plant can produce up to one billion grains of pollen.



Although the winter months largely offer a break from the seasonal allergies it doesn’t last long before we’re back into the tree pollen season in January again. However, as the winters get warmer the pollinating season is getting longer. This in turn means that the winter break from allergies is getting shorter every year.

How to Treat Allergies During the Houston Allergy Season

If your allergies keep getting you down then there’s no need to suffer in silence as there are a few steps that you can take to help you to cope. Although the two main aspects are prevention and medication, you could get an allergy test as it is easier to avoid your triggers if you know what they are. It’s also a good idea to speak to a healthcare professional and get their opinion. That said, there are several over-the-counter remedies that you can purchase. Antihistamine tablets are the most popular choice with the three main available types containing either loratadine, fexofenadine, or cetirizine.

However, regardless of whether you choose to take medication, the most important thing that you can do is try to avoid the allergens that trigger your symptoms — or at least limit your exposure to them. This includes simple things such as not going out when the pollen count is high and keeping your windows and doors closed to prevent pollen from entering your home. Plus, avoid airing your laundry outside as pollen can stick to the material. It’s also a good idea to avoid gardening or mowing the lawn. This is because it can stir up the allergens that irritate you. However, if you do spend time outdoors then you should wash your clothes as soon as you come indoors to get rid of any pollen that you’ve brought in with you.

Finally, keeping the air in your home clean is also helpful. This means using a dehumidifier or a high-efficiency particulate air (HEPA) filter.

The photo featured at the top of this post is ©

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About the Author

Hannah is a writer at A-Z animals where her primary focus is on reptiles, marine life, mammals, and geography. Hannah has been writing and researching animals for four years alongside running her family farm. A resident of the UK, Hannah loves riding horses and creating short stories.

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