San Mateo pollen forecast - today, tomorrow and the week ahead

Currently, there is no significant pollen in San Mateo.

On 17 July 2026, pollen conditions in San Mateo will be similar to today with no significant pollen expected.

According to the five-day outlook, cypress, grass, ambrosia, and artemisia pollen levels will increase later in the week.

On 16 July 2026, there are no significant pollen types in San Mateo.

San Mateo's pollen season opens with acacia and tree pollen from January in the mild San Francisco Peninsula climate. Oak follows through March and April, with grass peaking through April and May. The San Francisco Bay position means onshore westerly winds can periodically disperse pollen, while the Peninsula hills contribute substantial grass and tree pollen under offshore conditions. The dry summer largely suppresses mid-season pollen across the city.

The San Mateo pollen forecast is updated four times daily. See the timestamp below for the most recent update.

Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.

Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.

Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in San Mateo, modern forecasts combine recent measurements, weather data, and information about local vegetation.

This allows us to estimate pollen levels for today and the coming days, not just report the past.

Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.