October 24, 2023

Fall Allergies in Texas: Navigating Austin Allergens

Mountain cedar tree releasing pollen in Austin's fall season.

As the sweltering heat of Texas summer gives way to the mild and crisp air of fall, many residents eagerly anticipate the change in season. However, for those with allergies, this transition can be less than idyllic. The Lone Star State, with its vast ecological diversity, poses unique allergy challenges—especially in cities like Austin, San Antonio, and Corpus Christi. This post seeks to guide you through the allergenic landscapes of these cities during the autumn months.

Austin’s Allergic Landscape

Austin’s allergy problems primarily come from tree and weed pollens.

Mountain Cedar

Mountain cedar, scientifically known as Juniperus ashei, is especially notorious in the Central Texas region, including Austin, for causing what locals often refer to as “cedar fever.” Here’s why mountain cedar is particularly problematic for residents:

  • Prolific Pollen Producer: Mountain cedar trees produce a massive amount of pollen. Even a single tree can release millions of pollen grains, which, when carried by the wind, can inundate the area.
  • Wind-Pollinated: Unlike some other plants that rely on insects for pollination, mountain cedar is wind-pollinated. This means the trees produce lightweight pollen that is easily carried by the wind, spreading it over large distances.
  • Timing: Mountain cedar typically releases its pollen from December through February, a time when many other plants are not releasing pollen. This makes mountain cedar one of the primary culprits for winter allergies in the region.
  • Potency of Pollen: The pollen from mountain cedar is highly allergenic. This means that even a small amount of exposure can trigger allergic reactions in sensitive individuals.
  • Geographic Concentration: Central Texas, including the Austin area, has a high concentration of mountain cedar trees. The combination of the trees’ prolific pollen production and the dense population of these trees in the region means that the pollen counts can get extremely high.
  • Symptoms: The allergic reactions caused by mountain cedar can be more severe than typical hay fever symptoms. Symptoms can include runny nose, itchy and watery eyes, sneezing, and more. For some people, the reaction can be so severe that it feels like they have the flu, hence the term “cedar fever.”

Given the high density of mountain cedar trees in the region, combined with the nature and timing of their pollen release, many residents of Austin and surrounding areas find themselves grappling with significant allergy symptoms during the winter months.


Ragweed plants in Austin causing fall allergies.

Ragweed is a flowering plant in the Asteraceae family. There are multiple species of ragweed, but common ragweed (Ambrosia artemisiifolia) and giant ragweed (Ambrosia trifida) are among the most well-known for causing allergies.

Ragweed plants are often tall, with feather-like green leaves. They produce small, greenish-yellow flowers that produce vast amounts of pollen.

Allergy Implications in Austin:

  • Pollen Season: In Austin, ragweed pollen season typically begins in late summer and peaks in the fall, usually between August and November.
  • Prolific Pollinators: A single ragweed plant can produce up to 1 billion pollen grains in a season. This pollen is lightweight and can travel for miles, meaning even if you don’t have ragweed in your yard, the pollen can still reach you.
  • Symptoms: People allergic to ragweed will exhibit typical hay fever symptoms, including sneezing, nasal congestion, itchy or watery eyes, itchy throat, and coughing. For some, it can also exacerbate asthma symptoms.
  • Ragweed vs. Other Allergens: Austin’s allergenic landscape is diverse, with trees like mountain cedar, oak, and elm contributing to the pollen mix. While these trees have their specific pollinating seasons, ragweed adds to the allergenic load during the fall.

Factors Affecting Allergen Levels in Austin

Let’s delve deeper into the factors that influence pollen concentrations in Austin, particularly regarding its unique climate and rapid urban development.

Austin’s Unique Climate Patterns

Austin experiences a mix of humid subtropical and semi-arid climates. This results in hot summers and mild winters with periodic rainfall. The specific climate plays a role in when and how plants pollinate.

Rainfall can wash pollen out of the air, temporarily reducing pollen counts. However, rain also provides plants with the moisture they need to thrive. As plants flourish after a rain, they may release more pollen in the subsequent days, leading to a spike in pollen counts.

Rapid Urban Development

Austin skyline showcasing rapid urban development.

Urban development often involves the removal of native vegetation and its replacement with ornamental or non-native plants. These new plants might produce pollen that locals aren’t accustomed to, introducing new allergens to the environment.

As cities expand, there’s more concrete and fewer green spaces. Concrete surfaces and asphalt can heat up faster and retain heat, leading to the “urban heat island” effect. Elevated temperatures can extend the pollination season of some plants, causing them to release pollen for longer durations.

Urban areas can also affect local wind patterns and airflow. Polluted city air can trap pollen, preventing it from dispersing as effectively as it would in less developed areas. This trapping can lead to higher local pollen concentrations.

Impact of Rain on Pollen

Lightning in Austin, indicating rain's effect on pollen levels.

As mentioned, while rain can wash pollen out of the air, providing temporary relief, it gives plants the necessary hydration to produce and release more pollen afterward. This effect means that after a rain event, the subsequent days might see increased pollen counts.

Additionally, rain can increase mold spore production, especially if there are warm conditions following the rain. Mold can be another significant allergen for many people.

Resulting Challenge for Allergy Sufferers

With the combination of Austin’s climate, urban development patterns, and the effects of rain, allergy sufferers can face unpredictable and often heightened pollen and mold spore counts. It’s not just about the amount of pollen in the air, but the variety of allergens introduced due to urban landscaping choices and the extended durations for which these allergens are present.

In essence, the interplay of natural climatic conditions and human-induced changes in Austin creates a complex allergenic environment. The variability and intensity of allergens make it essential for those with allergies to monitor conditions and take preventive measures regularly.

Tips for Austin Residents

Monitor Pollen Counts

What are Pollen Counts? Pollen counts represent the amount of pollen present in the air, typically measured in grains of pollen per cubic meter of air over a 24-hour period. Knowing the pollen count can help allergy sufferers make informed decisions about outdoor activities.

Use Websites and Apps

Screenshot of Austin allergy report from an app.

Numerous websites and apps provide localized pollen count forecasts, often broken down by specific allergens like oak, ragweed, or grasses. Modern technology also allows for notifications. Some apps can send push notifications when pollen levels reach a particular threshold, helping users take preventive measures in real-time.

Optimal Times to Go Outdoors

Pollen release and its concentration in the air can vary throughout the day, depending on the type of plant and the prevailing weather conditions.

Early Morning and Late Evening

Generally, many plants release their pollen in the early morning hours. However, the pollen often doesn’t reach peak concentrations at ground level until later due to temperature and atmospheric conditions.

By late evening, much of the pollen has settled or been cleared from the air, leading to lower counts. Hence, for many regions, the air might have the lowest concentrations of pollen during these times.

It’s worth noting, though, that this can vary based on specific types of pollen. For instance, some grasses might release their pollen later in the morning.

Planning Activities

Man jogging in Austin park during high pollen season.

Knowing the optimal times to be outdoors can be especially helpful for those who exercise outside. Exercising increases the inhalation rate, which can intensify exposure to pollen. By scheduling activities during times of lower pollen concentrations, individuals can reduce their exposure and resultant symptoms.

Both monitoring pollen counts and understanding the optimal times to venture outdoors are proactive strategies that empower individuals to manage their allergy symptoms better. By leveraging technology and knowledge of plant behavior, allergy sufferers can optimize their daily routines, minimizing discomfort and disruptions.


The beauty of Texas in the fall is something to be enjoyed. Awareness, combined with preventive and corrective measures, ensures that everyone can relish the season.

In essence, while Texas offers a rich blend of ecosystems, with that comes a diverse set of allergens. But with awareness and proactive measures, residents can navigate the season with ease.

Greater Austin Allergy Asthma & Immunology