Low Pollen in O'Fallon, MO
Low today, mostly weed pollen.
Last updated August 14, 2026
What to do today
- It's a good day for outdoor activities since pollen levels are low.
- Do you know which plants cause your pollen allergy? Check out the pollen data to be prepared.
Forecast
About pollen in O'Fallon
Weed pollen is the main story in O'Fallon today, though it remains at a low level that most people won't notice much. Tree pollen is barely present at this point in the season, so any irritation you're feeling is more likely tied to weeds than anything coming from the trees. Looking ahead, weed pollen is expected to inch up over the next couple of days before easing slightly by the end of the stretch, while tree pollen should stay low to very low throughout. This pattern fits the calendar: with oak, maple, and other regional trees long past their spring peak, mid-August attention naturally shifts to weeds, particularly ragweed, which tends to build through late summer and into fall. For now, conditions remain mild overall, but it's a good stretch to keep an eye on how weed levels develop in the coming weeks.
Common questions
- What is the pollen count in O'Fallon, MO today?
- O'Fallon, MO is at a low 2 out of 5 on the Universal Pollen Index today, driven mainly by weed pollen. Over the next five days it ranges from 2 to 3 of 5.
- Is weed pollen high in O'Fallon, MO right now?
- Weed pollen is low today at 2 of 5, and it's past its peak season. Most people won't have symptoms.