Castelldefels pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Castelldefels is high; mugwort is high.
Pollen Tomorrow
Tomorrow (21 September 2026) levels are similar to today.
7-Day Trend
Over the next week mugwort will decrease; cypress, grass, and willow will remain stable.
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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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | High | 68/100 |
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) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | |
| Mugwort (Artemisia) | High | 70/100 |
Local Environmental Conditions
Castelldefels's coastal parks and the Llobregat delta corridor feature pine, tamarisk, and introduced trees as the main pollen sources alongside distinctive coastal dune vegetation, with exposure varying between these areas and the more built-up resort city centre. Surrounding Catalan Baix Llobregat farmland contribute substantial grass and crop pollen, while sea breezes frequently disperse pollen along the Barcelona suburban coastline.
Castelldefels's pollen season opens in January with pine and olive before grass from surrounding Catalan Baix Llobregat farmland peaks through April and May. The coastal dune position means strong onshore sea breezes frequently disperse pollen along the Barcelona suburban coastline, while the sub-Mediterranean climate concentrates pollen during spring with fewer rainfall interruptions than in Atlantic-facing Spanish cities.
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Frequently Asked Questions About Pollen in Catalonia
Is pollen high in Castelldefels right now?
On 20 September 2026, overall pollen levels in Castelldefels are high. Artemisia is the main contributor to airborne pollen
Will pollen levels change in Castelldefels tomorrow?
On 21 September 2026, pollen conditions in Castelldefels will be similar to today, with artemisia at high levels
Is pollen expected to decrease in Castelldefels this week?
According to the five-day outlook, artemisia pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.
Which pollen types are currently active in Castelldefels?
On 20 September 2026, Artemisia is the dominant pollen source in Castelldefels. cypress, grass, and willow are not currently active.
When is pollen season in Castelldefels?
How often is the Castelldefels pollen forecast updated?
The Castelldefels pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Castelldefels 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 Castelldefels 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 Castelldefels, 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).
