Foothill Ranch Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (6 October) pollen in Foothill Ranch is moderate; grass, ragweed, mold (alternaria), and mold (cladosporium) are moderate.
Pollen Tomorrow
Tomorrow (7 October 2026) grass remains moderate, ragweed remains moderate, mold (alternaria) remains moderate, mold (cladosporium) declining.
7-Day Trend
Over the next week mugwort, mold (alternaria), and mold (cladosporium) will increase; grass and ragweed will decrease.
Explore Forecasts
Air Quality & Mold
Pollen in Other Cities
Air Quality in Other Cities
Get More in Our App
Local pollen and air quality forecasts, interactive pollen maps and route profiles
Features and forecast availability vary by region.
Pollen Risk
Today - 6 October
| Pollen species | Level | Value |
|---|---|---|
| Alder (Alnus) | None | 0/100 |
| Birch (Betula) | None | 0/100 |
| Hazel (Corylus) | None | 0/100 |
| Cypress (Cupressaceae) | None | 0/100 |
| Grass (Poaceae) | Moderate | 28/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 39/100 |
| Alternaria | Moderate | 30/100 |
| Cladosporium | Moderate | 26/100 |
Tomorrow - 7 October
| Pollen species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alder (Alnus) | None | 0/100 | — |
| Birch (Betula) | None | 0/100 | — |
| Hazel (Corylus) | None | 0/100 | — |
| Cypress (Cupressaceae) | None | 0/100 | — |
| Grass (Poaceae) | Moderate | 28/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 40/100 | |
| Alternaria | Moderate | 26/100 | |
| Cladosporium | Low | 22/100 |
Local Environmental Conditions
The area around Foothill Ranch is a mix of scrubland and open grassland, plus some woodland. With running water close by, riverside trees such as willow, poplar and alder contribute to the local mix. Of the allergenic trees nearby, oak matters most, while plane tree also contributes. Grass pollen is significant here, and mugwort and pigweed contribute weed pollen.
Tree pollen peaks in early spring, when the weather warms to around 15°C and oak and plane tree are in full flower. Grass pollen follows, peaking in late spring and easing off by mid-fall. The season closes with mugwort and pigweed through summer. Spring is the wettest time of year, and heavy showers can bring short breaks in pollen.
Get pollen & AQ on Strava
Follow your environmental exposure and performance with the free Airmine-Strava integration. See your pollen and air quality exposure for every Strava activity.
Frequently Asked Questions About Pollen in California
Is pollen high in Foothill Ranch right now?
On 6 October 2026, overall pollen levels in Foothill Ranch are moderate. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in Foothill Ranch tomorrow?
On 7 October 2026, pollen conditions in Foothill Ranch will be similar to today, with ambrosia at moderate levels, grass at moderate levels
Is pollen expected to decrease in Foothill Ranch this week?
According to the five-day outlook, ambrosia and grass pollen levels are expected to gradually decrease, while artemisia pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in Foothill Ranch?
On 6 October 2026, Ambrosia is the dominant pollen source in Foothill Ranch. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in Foothill Ranch?
How often is the Foothill Ranch pollen forecast updated?
The Foothill Ranch pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Foothill Ranch 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 Foothill Ranch 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 Foothill Ranch, 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.
Understanding the Scale
The 0–100 pollen scores represent risk levels, not direct pollen measurements. Higher scores indicate higher risk.
Pollen
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
Get More in the Airmine Pollen app
Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
