Pollen Count in St. Louis, MO — Today
Updated Wednesday, October 21, 2026
The St. Louis pollen count today is 8 (Low). No single allergen is elevated today: tree, grass and weed pollen all read 0/0/0, and the only non-zero reading is mold at 3.7. The full split is tree pollen 0, grass pollen 0, weed pollen 0 and mold 3.7. The sections below break that headline number down by plant, by day and by what the band means in practice. Pollen Atlas updated this count on Wednesday, October 21, 2026.
A Low band on the Pollen Atlas index means the Total Pollen Index has stayed in the lower part of the 0–100 scale. Readings in this band are built from low individual category values rather than from one large spike, and the category split above matters more than the headline number: a low total can still contain one category, such as weed pollen or mold, reading noticeably higher than the rest, which is why the split is printed on every St. Louis page.
Mold is typically the least seasonal of the four categories on this page, in most years. Mold spores are associated with damp conditions and decaying plant material rather than a single pollination window, so mold can lead a reading in any month — and frequently does on otherwise quiet days, when tree, grass and weed pollen are all low. A mold-led total should not be read as a pollen surge; it is a different kind of reading, and the split above shows exactly how much of today’s total it accounts for.
To see whether today’s pollen level holds, check the 5-day St. Louis pollen forecast below — it is currently holding, with Sunday the highest day in the window.
What is the pollen count in St. Louis today?
The St. Louis pollen count today is 8 out of 100 (Low) on the Pollen Atlas Total Pollen Index, with no single allergen elevated today.
Total Pollen Index: 8 / 100 (Low)
Dominant allergen today: Tree
Pollen and mold levels
- Tree pollen: 0 (Low)
- Grass pollen: 0 (Low)
- Weed pollen (ragweed): 0 (Low)
- Mold: 3.7 (Moderate)
St. Louis 5-Day Pollen Forecast
| Day | Total Pollen Index | Band |
|---|---|---|
| Wednesday, October 21 | 8 | Low |
| Thursday, October 22 | 9 | Low |
| Friday, October 23 | 11 | Low |
| Saturday, October 24 | 16 | Low |
| Sunday, October 25 | 18 | Low |
Pollen Atlas forecasts St. Louis’s pollen count to peak on Sunday at 18 (Low) over the next 5 days.
Plants affecting St. Louis now
One plant is listed in today’s detail for St. Louis.
- Ragweed (weed): Universal Pollen Index 2 (Low) — out of season
Every pollen type, with photos and seasons: the pollen directory.
How to read this index
Pollen Atlas reports St. Louis on a Total Pollen Index from 0 to 100, built from separate tree, grass, weed and mold readings. The total is a summary, not an average of the four: a single strong category can lift it, and four quiet categories can hold it down whatever the month. Index values are supplied by AccuWeather data via Pollen Atlas and plant detail by the Google Pollen API, and figures update through the day, so a morning and an evening visit to this page can legitimately show different numbers.
Nearby cities
From Pollen Atlas News
See how St. Louis ranks against the worst pollen cities today
Pollen indexes: AccuWeather data via Pollen Atlas. Plant detail: Google Pollen API. Figures update through the day.