Gilroy pollen forecast - today, tomorrow and the week ahead

On 16 July 2026, overall pollen levels in Gilroy are low. Grass is the main contributor to airborne pollen

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

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

On 16 July 2026, Grass is the dominant pollen source in Gilroy. oak, willow, alder, ambrosia, artemisia, birch, and cypress are not currently active.

Gilroy's pollen season opens with acacia and tree pollen from January in the mild Santa Clara Valley climate. Oak follows through March and April, with grass peaking strongly through April and May from the surrounding agricultural valley. The valley setting channels prevailing northwesterly winds and marine air from San Francisco Bay, while surrounding farmland and the Diablo and Santa Cruz Mountain foothills contribute substantial grass and tree pollen.

The Gilroy 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 Gilroy, 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.