Union Reservoir East Campground, Arnold Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (6 October) pollen in Union Reservoir East Campground, Arnold is low; mold (alternaria) and mold (cladosporium) are low.
Pollen Tomorrow
Tomorrow (7 October 2026) mold (alternaria) remains low, mold (cladosporium) remains low, mugwort at low levels, ragweed at low levels.
7-Day Trend
Over the next week mugwort and ragweed will increase; mold (alternaria) and mold (cladosporium) will decrease; grass will remain stable.
Explore Forecasts
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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | None | 0/100 |
| Alternaria | Low | 7/100 |
| Cladosporium | Low | 11/100 |
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) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 2/100 | |
| Ragweed (Ambrosia) | Low | 5/100 | |
| Alternaria | Low | 8/100 | |
| Cladosporium | Low | 13/100 |
Local Environmental Conditions
The area around this site in Arnold is mostly woodland, with some open water. Close to the Union Reservoir, lakeside vegetation adds to local tree pollen. Oak heads the list of allergenic trees nearby, ahead of juniper. Undergrowth, clearings and woodland edges add smaller amounts of grass and herb pollen.
The pollen year opens with oak and juniper, peaking around late spring. Grasses are next, reaching their height around early summer and tailing off by late summer. The season closes with a lower weed peak from early summer into early fall, mostly from roadside and field-edge plants. Temperatures range from around freezing in the coldest month to around 20°C in the warmest, with most rain falling in the cooler months.
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.
Resource Hub
Frequently Asked Questions About Pollen in California
Is pollen high in Arnold right now?
Currently, there is no significant pollen in Arnold.
Will pollen levels change in Arnold tomorrow?
On 7 October 2026, pollen conditions in Arnold will be different from today, with ambrosia at low levels, artemisia at low levels
Is pollen expected to decrease in Arnold this week?
According to the five-day outlook, ambrosia and artemisia pollen levels will increase later in the week.
Which pollen types are currently active in Arnold?
On 6 October 2026, there are no significant pollen types in Arnold.
When is pollen season in Arnold?
How often is the Arnold pollen forecast updated?
The Arnold pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Arnold 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 Arnold 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 Arnold, 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).
