Texas presents a unique challenge for individuals with environmental sensitivities because its allergy season is not confined to the traditional spring and fall periods found in other parts of the country. The state’s immense size and subtropical to arid climate variations create conditions where plants can release pollen almost year-round. This extended growing season means that as one major allergen subsides, another is often ready to take its place, making Texas a difficult place for those who suffer from seasonal allergies. The diversity of the state’s plant life and the lack of a prolonged, hard freeze contribute to this persistent cycle.
Winter and Early Spring Allergy Peaks
The state’s allergy calendar often begins with a major peak from late December to early March, an unusual time when other regions experience a complete break from pollen. This intense period is defined by the massive release of pollen from the Mountain Cedar (Juniperus ashei), commonly known as “Cedar Fever.” Mountain Cedar is highly concentrated across the Central Texas Hill Country, including metropolitan areas like Austin and San Antonio. The male trees produce vast quantities of pollen, which can travel for hundreds of miles on dry, windy days.
This potent pollen triggers severe symptoms such as incessant sneezing, sinus congestion, a runny nose, and fatigue. Despite the common name, “Cedar Fever” is an intense allergic reaction that typically does not involve a true fever, although it can be mistaken for a winter cold or flu. The season for this specific juniper species begins as early as mid-November and typically reaches its peak concentration throughout January.
Late Spring and Summer Allergy Triggers
As the Mountain Cedar subsides, the allergy burden transitions seamlessly into the traditional spring tree pollen season, which runs from approximately February or March through May. Tree pollens from species like Oak, Elm, and Ash become the dominant airborne irritants during these months across the state. Oak trees are particularly prolific in Texas, shedding a fine, yellowish-green dust that coats cars and outdoor surfaces, contributing to high pollen counts.
Following the tree pollen wave, grass pollens take over as the primary summer trigger, remaining active from April through September. Grasses such as Bermuda grass and Johnson grass thrive in the state’s warm weather and are widespread in lawns and along roadsides. Furthermore, the warm, humid conditions prevalent throughout the summer months, especially in Eastern and Coastal Texas, create an ideal environment for mold spores. This mold growth is driven by consistent moisture and high temperatures rather than decaying vegetation.
Autumn Allergy Season: Weeds and Mold
The final significant allergy surge of the year occurs in the late summer and autumn, roughly spanning from August through November. This period is dominated by weed pollens, with Ragweed being the most common and potent offender across Texas. Ragweed begins releasing its lightweight, highly allergenic pollen in mid-August and typically reaches its peak concentration during September and October.
A single Ragweed plant can produce up to one billion pollen grains in a season, allowing the microscopic pollen to travel for hundreds of miles on the wind. As temperatures drop and leaves begin to decay in the autumn, a secondary spike in outdoor mold spores occurs. This final seasonal mold surge is tied to the decomposition of plant matter and damp soil.
How Location Within Texas Impacts Severity
Texas is far too large and ecologically diverse for a single, uniform allergy calendar to apply to all residents. The specific mix and intensity of allergens shift dramatically based on geographic location within the state. Central Texas, for instance, is uniquely burdened by the severe Mountain Cedar allergy during the winter months due to the high density of Juniperus ashei in the Hill Country.
In contrast, the humid, subtropical climate of East and Coastal Texas fosters year-round allergy conditions, with high levels of mold spores and extended seasons for grasses and trees. The proximity to the Gulf of Mexico contributes to the persistent moisture that encourages this fungal growth. Conversely, the arid conditions of West Texas and the Panhandle result in lower tree and grass pollen counts but an increased presence of desert-specific allergens, such as tumbleweed and sagebrush, along with dust stirred up by persistent winds.