San Jose pollen forecast — Downtown San Jose neighborhood

On 9 August 2026, overall pollen levels in San Jose are moderate. Ambrosia is the main contributor to airborne pollen, while artemisia, cypress, and grass remain at lower levels

On 10 August 2026, pollen conditions in San Jose will be different from today, with ambrosia, artemisia continuing to decline

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

On 9 August 2026, Ambrosia is the dominant pollen source in San Jose. artemisia, cypress, and grass are also present but at lower levels.

Situated a neighborhood in San Jose, Downtown San Jose shares the area's pollen timeline, beginning with acacia and oak in January with olive following close behind through February and March. Grass follows, peaking through March and April, while light weed pollen continues into early autumn. A long dry summer follows the spring peak, holding pollen counts low until autumn rains return, consistent with the wider San Jose area.

The San Jose 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 Jose, 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.