Penn Valley Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (6 October) pollen in Penn Valley is moderate; grass and mold (cladosporium) are moderate; mugwort, ragweed, and mold (alternaria) are low.
Pollen Tomorrow
Tomorrow (7 October 2026) levels are similar to today.
7-Day Trend
Over the next week mugwort will increase; grass, ragweed, mold (alternaria), and mold (cladosporium) 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 | 45/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 12/100 |
| Ragweed (Ambrosia) | Low | 25/100 |
| Alternaria | Low | 24/100 |
| 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 | 40/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 8/100 | |
| Ragweed (Ambrosia) | Low | 22/100 | |
| Alternaria | Low | 25/100 | |
| Cladosporium | Moderate | 37/100 |
Local Environmental Conditions
This site in Penn Valley is surrounded mainly by woodland, which covers around 68% of the nearby area, with a good deal of open grassland. With a watercourse close by, riverside vegetation contributes to the local mix. Of the trees nearby, oak is the one that matters most for allergies. Grasses add a sizeable share of the local pollen.
Oak leads the season in mid-spring, as temperatures climb to around 15°C, and tree pollen reaches its peak. Then come the grasses, strongest in late spring and fading by early fall. Weeds on open ground add a smaller late peak from early summer into early fall. 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 Penn Valley right now?
On 6 October 2026, overall pollen levels in Penn Valley are moderate. Grass is the main contributor to airborne pollen, while ambrosia and artemisia remain at lower levels
Will pollen levels change in Penn Valley tomorrow?
On 7 October 2026, pollen conditions in Penn Valley will be similar to today, with grass at moderate levels, ambrosia at low levels, artemisia at low levels
Is pollen expected to decrease in Penn Valley this week?
According to the five-day outlook, grass and ambrosia 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 Penn Valley?
On 6 October 2026, Grass is the dominant pollen source in Penn Valley. ambrosia and artemisia are also present but at lower levels.
When is pollen season in Penn Valley?
How often is the Penn Valley pollen forecast updated?
The Penn Valley pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Penn 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 Penn 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 Penn 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.
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).
