Common Houston Allergens
Measured counts from the Houston Health Department · Wednesday, September 23, 2026
This is the full list of pollen and mold types the City of Houston's monitoring station identifies and counts, with today's measured value for each. Trees and weeds are reported down to the genus; mold is reported by spore type. Grass is counted as a single total rather than by individual species.
Trees
| Allergen | Today |
|---|---|
| Maple (Acer) | 0 |
| Alder (Alnus) | 0 |
| Birch (Betula) | 0 |
| Hickory/Pecan (Carya) | 0 |
| Hackberry (Celtis) | 0 |
| Hazelnut (Corylus) | 0 |
| Cedar (Cupressaceae) | 0 |
| Ash (Fraxinus) | 0 |
| Walnut (Juglans) | 0 |
| Sweet Gum (Liquidambar) | 0 |
| Mulberry (Morus) | 0 |
| Pine (Pinaceae) | 0 |
| Sycamore (Platanus) | 0 |
| Cottonwood (Populus) | 0 |
| Oak (Quercus) | 0 |
| Willow (Salix) | 0 |
| Linden (Tilia) | 0 |
| Elm (Ulmus) | 0 |
| Other Tree | 0 |
Weeds
| Allergen | Today |
|---|---|
| Ragweed (Ambrosia) | 84 |
| Other Weed | 4 |
| Amaranth (Chenopodiaceae/ Amaranthaceae) | 2 |
| Sage (Artemisia) | 0 |
| Aster (Asteraceae) | 0 |
| Sedge (Cyperaceae) | 0 |
| Plantain (Plantago) | 0 |
| Sheep Sorel (Rumex) | 0 |
| Cattail (Typha) | 0 |
| Nettle (Urticaceae) | 0 |
Mold
| Allergen | Today |
|---|---|
| Ascospores | 4,355 |
| Cladosporium | 2,168 |
| Basidiomycetes | 1,026 |
| Curvularia | 271 |
| Penicillium/Aspergillus | 166 |
| Nigrospora | 133 |
| Cercospora | 127 |
| Periconia | 42 |
| Smuts/Myxomycete | 40 |
| Dreshslera/Helminthosporium | 20 |
| Alternaria | 18 |
| Pithomyces | 12 |
| Rust | 8 |
| Spegazinia | 8 |
| Tetraploa | 8 |
| Oidium/Erysiphe(Powdery Mildew) | 6 |
| Torula | 2 |
| Algae | 0 |
| Epicoccum | 0 |
| Stemphyllium | 0 |
How to use this list
Allergists often test for the specific pollens and molds that matter in your region. Seeing which ones are actually elevated on a bad day can help you connect your symptoms to a likely trigger — for example,oak in spring, ragweed in fall, or Cladosporium after a humid stretch. For the headline category levels and trends, see thefull report and the trends page. This site is informational and isn't a substitute for advice from a board-certified allergist.