Very Low Pollen in San Mateo, CA
Very low today, mostly grass pollen.
Last updated September 29, 2026
What to do today
- Pollen levels are very low right now. It's a great day to enjoy the outdoors!
Forecast
About pollen in San Mateo
Grass pollen is the only type registering in San Mateo today, and levels are quite low. Most people, including those with sensitivities, should notice little to no irritation outdoors. Looking ahead, grass pollen is expected to hold at these low levels through the next several days, offering a stretch of easy conditions for anyone prone to seasonal symptoms. This tracks with the time of year: the region's tree pollen, from species like oak and birch, typically peaked back in spring, while grasses saw their heaviest activity in late spring and early summer. As autumn settles in, overall pollen tends to quiet down, though weeds such as ragweed can still stir occasionally through the fall season.
Common questions
- What is the pollen count in San Mateo, CA today?
- San Mateo, CA is at a very low 1 out of 5 on the Universal Pollen Index today, driven mainly by grass pollen. The five-day outlook holds steady around 1 of 5.
- Is grass pollen high in San Mateo, CA right now?
- Grass pollen is very low today at 1 of 5, and it's past its peak season. Most people won't notice it.