Rancho Cucamonga pollen forecast - today, tomorrow and the week ahead

Today (9 August) pollen in Rancho Cucamonga is medium; ragweed is medium; cypress, grass, and mugwort are low. Tomorrow (10 August 2026) levels are similar - mugwort remains low, ragweed declining. Over the following five days grass, mugwort, and ragweed will increase; cypress will remain stable. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.

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Rancho Cucamonga's parks, including Central Park and the Cucamonga Creek corridor, feature oak, sycamore, and introduced eucalyptus as the main tree pollen sources, with exposure varying between these green areas and the more built-up city centre. Surrounding Inland Empire chaparral and the San Gabriel Mountain foothills contribute substantial grass and scrub pollen, while Santa Ana winds can concentrate pollen across the area.

Today - 9 August

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    Low

    3/100

  • Grass (Poaceae):

    Low

    3/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    Low

    19/100

  • Ragweed (Ambrosia):

    Medium

    31/100

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 - 10 August

  • 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

  • Mugwort (Artemisia):

    Low

    10/100

  • Ragweed (Ambrosia):

    Low

    24/100

Air quality in Rancho Cucamonga

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Frequently Asked Questions

Is pollen high in Rancho Cucamonga right now?

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

Will pollen levels change in Rancho Cucamonga tomorrow?

On 10 August 2026, pollen conditions in Rancho Cucamonga will be different from today, with artemisia at low levels and ambrosia continuing to decline

Is pollen expected to decrease in Rancho Cucamonga this week?

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

Which pollen types are currently active in Rancho Cucamonga?

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

When is pollen season in Rancho Cucamonga?
Rancho Cucamonga's pollen season opens with acacia and native oak from January in the mild Inland Empire climate. Sycamore and grass follow through March and April, with the season peaking earlier than most US cities. The San Gabriel Mountain foothills channel airflows and concentrate pollen, while surrounding chaparral contributes substantial scrub pollen. Santa Ana winds can concentrate pollen across the area under offshore conditions.
How often is the Rancho Cucamonga pollen forecast updated?

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

Does pollen in Rancho Cucamonga 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 Rancho Cucamonga 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 Rancho Cucamonga, 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: 10 August 2026 at 02:34 CEST (Data is updated four times daily.)

This page provides the latest public pollen forecast for Rancho Cucamonga.

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

Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.