Simi Hills Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (6 October) pollen in Simi Hills is moderate; grass, ragweed, mold (alternaria), and mold (cladosporium) are moderate; mugwort is low.
Pollen Tomorrow
Tomorrow (7 October 2026) levels are similar to today.
7-Day Trend
Over the next week mugwort and mold (cladosporium) will increase; grass, ragweed, and mold (alternaria) will decrease.
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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 | 29/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 4/100 |
| Ragweed (Ambrosia) | Moderate | 46/100 |
| Alternaria | Moderate | 37/100 |
| Cladosporium | Moderate | 36/100 |
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 | 27/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 3/100 | |
| Ragweed (Ambrosia) | Moderate | 45/100 | |
| Alternaria | Moderate | 34/100 | |
| Cladosporium | Moderate | 33/100 |
Local Environmental Conditions
The heart of Simi Hills is surrounded mainly by open grassland, which covers around 61% of the nearby area, with some scrubland. A watercourse nearby means riverside trees such as willow are part of the local pollen picture. Among allergenic trees nearby, oak is the main source. Grass pollen is significant here, and mugwort and pigweed contribute weed pollen.
Oak leads the season in early spring, as temperatures climb to around 15°C, and tree pollen reaches its peak. Grass pollen follows, peaking in late spring and easing off by mid-fall. Later, mugwort and pigweed keep weed pollen in the air through summer. Rain is heaviest in winter, often giving short breaks from high pollen levels.
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Frequently Asked Questions About Pollen in California
Is pollen high in Simi Hills right now?
On 6 October 2026, overall pollen levels in Simi Hills are moderate. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Simi Hills tomorrow?
On 7 October 2026, pollen conditions in Simi Hills will be similar to today, with ambrosia at moderate levels, artemisia at low levels, grass at moderate levels
Is pollen expected to decrease in Simi Hills 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 Simi Hills?
On 6 October 2026, Ambrosia is the dominant pollen source in Simi Hills. grass and artemisia are also present but at lower levels.
When is pollen season in Simi Hills?
How often is the Simi Hills pollen forecast updated?
The Simi Hills pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Simi Hills 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 Simi Hills 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 Simi Hills, 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).
