Castro Valley pollen forecast - today, tomorrow and the week ahead

Today (25 June) pollen in Castro Valley is none Tomorrow (26 June 2026) levels are similar. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.

For long term forecasts and maps, see the Airmine app

Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

Castro Valley's East Bay California setting features blue oak, California bay, and eucalyptus as the main tree pollen sources, with exposure varying between the extensively wooded chaparral hillsides of the Castro Valley hills and the more built-up commercial corridors along Castro Valley Boulevard. The elevation gradient between the oak and bay woodland above and the valley floor below creates distinct local pollen zones throughout the spring season.

Today - 25 June

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    None

    0/100

  • Willow (Salicaceae):

    None

    0/100

High pollen levels may trigger sneezing, itchy eyes, and congestion. Airmine's neighbourhood estimates use satellites to map local vegetation and a statistical prediction model, updated four times daily.

Tomorrow - 26 June

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    None

    0/100

  • Willow (Salicaceae):

    None

    0/100

Frequently Asked Questions

Is pollen high in Castro Valley right now?

Currently, there is no significant pollen in Castro Valley.

Will pollen levels change in Castro Valley tomorrow?

On 26 June 2026, pollen conditions in Castro Valley will be similar to today with no significant pollen expected.

Is pollen expected to decrease in Castro Valley this week?

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

Which pollen types are currently active in Castro Valley?

On 25 June 2026, there are no significant pollen types in Castro Valley.

When is pollen season in Castro Valley?
Castro Valley's East Bay California setting produces a season opening in January with oak and olive before grass from surrounding Alameda County land peaks through April and May. Mugwort extends exposure into September, while the bay proximity moderates temperatures and the East Bay hills channel the Delta breeze that can periodically suppress or intensify pollen dispersal throughout the spring season.
How often is the Castro Valley pollen forecast updated?

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

Does pollen in Castro Valley come from nearby or far away?

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.

Are pollen levels in Castro Valley based on measurements or forecasts?

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 Castro Valley, 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.

Want to see pollen forecasts for other cities in United States?

Check pollen in other popular cities:

Data provided by Airmine — Last update: 25 Jun 2026, 09:01 CET (Data is updated four times daily.)

This page provides the latest public pollen forecast for Castro Valley.

For long term forecasts and maps, see the Airmine app

Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.