Houston, TX Pollen Levels Today

Houston's humid subtropical climate, mild winters, and Gulf Coast proximity create one of the most challenging allergy environments in the United States, with an extended pollen season that often spans nearly the entire year.

Tree pollen kicks off as early as December and dominates through spring, with mountain cedar (ashe juniper) triggering the notorious "cedar fever" in January, followed by oak, pine, ash, elm, pecan, and mulberry peaking from February through April—oak alone can blanket the city in visible yellow pollen.

As trees taper, grass pollen takes over from late April through summer and into early fall, driven primarily by Bermuda, Johnson, Bahia, and ryegrass, with Bermuda often producing symptoms well into October thanks to Houston's long warm season.

Weed pollen rises sharply in late summer and fall, with ragweed leading the charge from August through November, alongside pigweed, lamb's quarters, and marsh elder. Overlap between lingering grasses and emerging weeds in late summer frequently intensifies symptoms.

Beyond pollen, Houston's persistent humidity fuels year-round mold growth (especially Alternaria and Cladosporium), while dust mites, urban air pollution, and ozone further aggravate respiratory allergies.

Overall, Houston's allergy profile is defined by a long, overlapping, high-intensity season compounded by humidity and mold.