Harbor City Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (10 October) pollen in Harbor City is high; ragweed is high; grass, mold (alternaria), and mold (cladosporium) are low.
Pollen Tomorrow
Tomorrow (11 October 2026) mold (alternaria) remains low, mold (cladosporium) remains low, ragweed declining, grass no longer expected.
7-Day Trend
Over the next week grass, mugwort, ragweed, mold (alternaria), and mold (cladosporium) will increase.
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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 | 7/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | High | 51/100 |
| Mold (Alternaria) | Low | 14/100 |
| Mold (Cladosporium) | Low | 19/100 |
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) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 40/100 | |
| Mold (Alternaria) | Low | 10/100 | |
| Mold (Cladosporium) | Low | 19/100 |
Local Environmental Conditions
This part of Harbor City is densely built up. The leading allergenic tree nearby is oak, with olive and willow close behind. Beyond the trees, grasses matter a great deal, and mugwort and pigweed are the main weed sources. Mugwort is unusually common here compared with most other locations, making it a particularly important local pollen source.
Tree pollen peaks in mid-spring, when the weather warms to around 15°C and oak, olive and willow are in full flower. Grass pollen follows, peaking in late spring and easing off by early fall. The most intense period comes through summer, when mugwort and pigweed are in flower. Rain is heaviest in winter, often giving short breaks from high pollen levels.
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Frequently Asked Questions About Pollen in California
Is pollen high in Harbor City right now?
On 10 October 2026, overall pollen levels in Harbor City are high. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in Harbor City tomorrow?
On 11 October 2026, pollen conditions in Harbor City will be different from today, with ambrosia continuing to decline
Is pollen expected to decrease in Harbor City this week?
According to the five-day outlook, artemisia, grass, and ambrosia pollen levels will increase later in the week.
Which pollen types are currently active in Harbor City?
On 10 October 2026, Ambrosia is the dominant pollen source in Harbor City. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in Harbor City?
How often is the Harbor City pollen forecast updated?
The Harbor City pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Harbor City 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 Harbor City 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 Harbor City, 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).
