Sterling, Illinois pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Sterling, Illinois is moderate; ragweed is moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed declining.
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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 37/100 |
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) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 25/100 |
Local Environmental Conditions
Sterling's setting on a river town along the Rock River in northern Illinois supports riverside cottonwood, oak woodlots, and farmland grasses as the leading local vegetation, all factoring into the pollen count through the year. Local parks and open ground tend to see higher pollen counts than the denser urban core. Residents who spend time outdoors around Sterling typically notice the shift as each season turns over.
Sterling's pollen season opens with maple and elm from March then oak follows, running through April. Grass pollen then peaks through May and June, and a late-summer ragweed peak runs into September. Warm, humid summers in this part of the Midwest favor a pronounced late-season ragweed peak throughout the year.
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Frequently Asked Questions About Pollen in Illinois
Is pollen high in Sterling, Illinois right now?
On 20 September 2026, overall pollen levels in Sterling, Illinois are moderate. Ambrosia is the main contributor to airborne pollen
Will pollen levels change in Sterling, Illinois tomorrow?
On 21 September 2026, pollen conditions in Sterling, Illinois will be different from today, with ambrosia continuing to decline
Is pollen expected to decrease in Sterling, Illinois 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 Sterling, Illinois?
On 20 September 2026, Ambrosia is the dominant pollen source in Sterling, Illinois. artemisia and grass are not currently active.
When is pollen season in Sterling, Illinois?
How often is the Sterling, Illinois pollen forecast updated?
The Sterling, Illinois pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Sterling, Illinois 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 Sterling, Illinois 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 Sterling, Illinois, 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).
