Riverside pollen forecast — Hollywood neighborhood
Pollen Today
Today (20 September) pollen in Hollywood, Riverside is moderate; grass and ragweed are moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed remains moderate, grass declining.
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) | Moderate | 34/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 43/100 |
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 | 20/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 28/100 |
Local Environmental Conditions
Hollywood — Here, not far off, about 524m out, water here is bordered by hazel and willow, both notable sources of wind-borne pollen. Woodland dominated by oak and birch, with birch a leading regional tree-pollen allergen; this sits at around 323m distant. Located positioned about 414m from the neighborhood, this area has a green space of mown lawn and planted trees, both feeding into local grass and ragweed counts.
Hazel and willow by the water are typically first out of the gate, building through the tail end of winter into March. Once hazel fades, oak and birch in the woods carry the season forward, usually peaking from April into May. Grass pollen takes over next, building to a peak around June, with ragweed then rising to the fore from mid-August through October.
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
Frequently Asked Questions About Pollen in Illinois
Is pollen high in Riverside right now?
On 20 September 2026, overall pollen levels in Riverside are moderate. Grass is the main contributor to airborne pollen, while ambrosia remain at lower levels
Will pollen levels change in Riverside tomorrow?
On 21 September 2026, pollen conditions in Riverside will be different from today, with ambrosia at moderate levels and grass continuing to decline
Is pollen expected to decrease in Riverside 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 Riverside?
On 20 September 2026, Grass is the dominant pollen source in Riverside. ambrosia are also present but at lower levels. artemisia are not currently active.
When is pollen season in Riverside?
How often is the Riverside pollen forecast updated?
The Riverside pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Riverside 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 Riverside 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 Riverside, 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).
