Tree pollen
None
0 grains/m³
A real, measured count — not a model. The Houston Health Department laboratory (a certified National Allergy Bureau counting station) samples the air continuously and publishes the count every weekday morning. It's a regional reading: pollen travels, so the Houston count is the right guidance for Crosby air.
Count for Thursday, Jul 16 · new counts publish weekday mornings.
None
0 grains/m³
Low
6 grains/m³
Medium
6 grains/m³
Heavy
13,823 spores/m³
Only types the lab actually counted today are listed (names as the lab reports them).
Categories follow the National Allergy Bureau scale — None, Low, Medium, Heavy, Extremely Heavy — and the thresholds differ by type, because it takes far fewer grass grains than mold spores to bother people:
| Low | Medium | Heavy | Extremely Heavy | |
|---|---|---|---|---|
| Grass pollen | 1–4 | 5–19 | 20–199 | 200+ |
| Weed pollen | 1–9 | 10–49 | 50–499 | 500+ |
| Tree pollen | 1–14 | 15–89 | 90–1,499 | 1,500+ |
| Mold spores | 1–6,499 | 6,500–12,999 | 13,000–49,999 | 50,000+ |
Tree pollen dominates mid-January through mid-April (oak, elm, pine — and cedar elm makes a second run in September–October). Grass pollen runs long here, spring through fall. Ragweed and other weeds peak in the fall. Mold spores are the year-round constant on the humid Gulf Coast — counts jump after rain and in the muggy summer, which is why a Heavy mold day in July is common.
On high days: mornings are usually worst for pollen, rain knocks pollen down (but pushes mold up a day or two later), and windy dry days spread everything. If you're sensitive, check the count before yard work and keep windows closed on Heavy days.