Olinda, Brea Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (10 October) pollen in Olinda, Brea is moderate; ragweed is moderate; grass, mold (alternaria), and mold (cladosporium) are low.
Pollen Tomorrow
Tomorrow (11 October 2026) grass remains low, mold (alternaria) remains low, mold (cladosporium) remains low, ragweed declining.
7-Day Trend
Over the next week grass, mugwort, ragweed, and mold (cladosporium) will increase; mold (alternaria) will decrease.
Explore Forecasts
Air Quality & Mold
Pollen for Neighborhoods
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 - 10 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) | Low | 8/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 31/100 |
| Mold (Alternaria) | Low | 21/100 |
| Mold (Cladosporium) | Low | 24/100 |
Tomorrow - 11 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) | Low | 1/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 24/100 | |
| Mold (Alternaria) | Low | 20/100 | |
| Mold (Cladosporium) | Low | 24/100 |
Local Environmental Conditions
The area around this part of Brea is mostly open grassland, with a good deal of woodland. A nearby park adds mown lawns and planted trees to the local pollen mix. Of the allergenic trees nearby, oak matters most, while plane tree and willow also contribute. Grasses are a major source, with mugwort and pigweed adding to the weed pollen load.
Oak, plane tree and willow lead the season in mid-spring, as temperatures climb to around 15°C, and tree pollen reaches its peak. Grasses take over in late spring, with temperatures around 20°C, and their pollen lingers into early 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.
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 Brea right now?
On 10 October 2026, overall pollen levels in Brea are moderate. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in Brea tomorrow?
On 11 October 2026, pollen conditions in Brea will be different from today, with grass at low levels and ambrosia continuing to decline
Is pollen expected to decrease in Brea this week?
According to the five-day outlook, ambrosia, artemisia, and grass pollen levels will increase later in the week.
Which pollen types are currently active in Brea?
On 10 October 2026, Ambrosia is the dominant pollen source in Brea. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in Brea?
How often is the Brea pollen forecast updated?
The Brea pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Brea 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 Brea 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 Brea, 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).
