San Clemente pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in San Clemente is high; ragweed is high; grass is moderate; mugwort is low.
Pollen Tomorrow
Tomorrow (21 September 2026) grass remains moderate, ragweed remains high, mugwort no longer expected.
7-Day Trend
Over the next week grass, mugwort, and ragweed will increase.
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Pollen Risk
Today - 20 September
| 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 | 48/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 9/100 |
| Ragweed (Ambrosia) | High | 70/100 |
Tomorrow - 21 September
| 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 | 39/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | High | 62/100 |
Local Environmental Conditions
San Clemente's coastal Orange County setting features coastal sage scrub, Torrey pine, and eucalyptus as the main pollen sources, with exposure varying between the coastal sage-covered canyon slopes and the more built-up beach community areas along El Camino Real. The San Mateo Creek canyon provides locally significant green space, while the very strong Pacific marine influence creates one of the most reliably moderated coastal pollen environments in Southern California throughout.
San Clemente's coastal Orange County California setting produces a season opening in January with olive and coastal sage before grass from surrounding coastal land peaks through March and April. Mugwort extends exposure into September, while the very strong Pacific marine influence moderates temperatures year-round and onshore ocean breezes frequently provide the most reliably moderated pollen environment in the Southern California coastal zone.
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Resource Hub
Pollen forecast neighborhoods 3 neighborhoods
Frequently Asked Questions About Pollen in California
Is pollen high in San Clemente right now?
On 20 September 2026, overall pollen levels in San Clemente are high. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in San Clemente tomorrow?
On 21 September 2026, pollen conditions in San Clemente will be different from today, with ambrosia at high levels, grass at moderate levels
Is pollen expected to decrease in San Clemente 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 San Clemente?
On 20 September 2026, Ambrosia is the dominant pollen source in San Clemente. grass and artemisia are also present but at lower levels.
When is pollen season in San Clemente?
How often is the San Clemente pollen forecast updated?
The San Clemente pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in San Clemente 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 San Clemente 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 San Clemente, 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 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
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).
