El Cajon pollen forecast — Grossmont HS's Baseball Diamond neighborhood
Pollen Today
Today (20 September) pollen in Grossmont HS's Baseball Diamond, El Cajon is high; ragweed is high; grass is moderate; mugwort is low.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed remains high, grass declining, 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 | 35/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 8/100 |
| 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) | Low | 24/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | High | 60/100 |
Local Environmental Conditions
Grossmont HS's Baseball Diamond is set in the El Cajon suburban landscape of eastern San Diego County, with oak, eucalyptus, and coastal sage scrub as the main surrounding pollen sources. Surrounding chaparral and canyon vegetation in the Grossmont area contribute substantial grass and scrub pollen, while the warm inland valley climate advances the season compared to coastal San Diego and canyon winds can concentrate pollen throughout.
Grossmont HS's Baseball Diamond's pollen season lines up with the rest of El Cajon, starting with olive and acacia in January with eucalyptus taking the lead through February. Grass follows, peaking through March and April, while light weed pollen carries into September. The Southern California Mediterranean climate advances the season, and onshore Pacific breezes can periodically disperse pollen throughout the year.
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Frequently Asked Questions About Pollen in California
Is pollen high in El Cajon right now?
On 20 September 2026, overall pollen levels in El Cajon are high. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in El Cajon tomorrow?
On 21 September 2026, pollen conditions in El Cajon will be different from today, with ambrosia at high levels and grass continuing to decline
Is pollen expected to decrease in El Cajon 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 El Cajon?
On 20 September 2026, Ambrosia is the dominant pollen source in El Cajon. grass and artemisia are also present but at lower levels.
When is pollen season in El Cajon?
How often is the El Cajon pollen forecast updated?
The El Cajon pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in El Cajon 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 El Cajon 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 El Cajon, 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).
