San Francisco pollen forecast — USS San Francisco Memorial neighborhood
Pollen Today
Today (20 September) pollen in USS San Francisco Memorial, San Francisco is none
Pollen Tomorrow
Tomorrow (21 September 2026) grass at low levels, mugwort at low levels, ragweed at low levels.
7-Day Trend
Over the next week grass, mugwort, and ragweed will increase.
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 - 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) | None | 0/100 |
| Ragweed (Ambrosia) | None | 0/100 |
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 | 3/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 3/100 | |
| Ragweed (Ambrosia) | Low | 3/100 |
Local Environmental Conditions
Here, in the surrounding area, a waterway supports coast live oak and sycamore along its bank, both notable sources of wind-borne pollen. This area, a short distance from here, has a stand of coast live oak and bay laurel, oak ranked among the region's more notable tree allergens. This park's mix of turf and landscaped trees contributes a modest grass and ragweed pollen load, in the vicinity.
Average temperatures range from about 10°C in January to 18°C in August, and most of the 564 mm annual rainfall falls in the cooler months around January. Pollen activity typically picks up as temperatures climb out of the January low, from around February onward.
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
Pollen forecast neighborhoods 264 neighborhoods
Sports venues in San Francisco 3 sports venues
Frequently Asked Questions About Pollen in California
Is pollen high in San Francisco right now?
Currently, there is no significant pollen in San Francisco.
Will pollen levels change in San Francisco tomorrow?
On 21 September 2026, pollen conditions in San Francisco will be different from today, with ambrosia at low levels, artemisia at low levels, grass at low levels
Is pollen expected to decrease in San Francisco 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 Francisco?
On 20 September 2026, there are no significant pollen types in San Francisco.
When is pollen season in San Francisco?
How often is the San Francisco pollen forecast updated?
The San Francisco pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in San Francisco 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 Francisco 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 Francisco, 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).
