Crest Hill pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Crest Hill is moderate; grass and ragweed are moderate; mugwort is low.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed remains moderate, grass declining, mugwort no longer expected.
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) | Moderate | 33/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 3/100 |
| 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 | 15/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 26/100 |
Local Environmental Conditions
Crest Hill lies in the Calumet-Kankakee lowlands south of Chicago, not far from Marley Creek and Goodenow Grove Forest Preserve. The surrounding landscape is dominated by floodplain cottonwood and old-field prairie. Marley Creek winds through the wider area, its banks favoring moisture-loving trees such as willow and alder. Local vegetation still varies with soil type and drainage.
Trees along Marley Creek, such as willow and alder, are usually first to release pollen, typically peaking in late winter into March. The wooded areas near Kankakee River State Park then carry the tree pollen load into its sharpest phase, typically centered on April and May. Farther out toward the Little Calumet River and Goodenow Grove Forest Preserve, tree pollen tends to follow this same rough schedule.
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Pollen forecast neighborhoods 2 neighborhoods
Frequently Asked Questions About Pollen in Illinois
Is pollen high in Crest Hill right now?
On 20 September 2026, overall pollen levels in Crest Hill are moderate. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Crest Hill tomorrow?
On 21 September 2026, pollen conditions in Crest Hill will be different from today, with ambrosia at moderate levels and grass continuing to decline
Is pollen expected to decrease in Crest Hill 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 Crest Hill?
On 20 September 2026, Ambrosia is the dominant pollen source in Crest Hill. grass and artemisia are also present but at lower levels.
When is pollen season in Crest Hill?
How often is the Crest Hill pollen forecast updated?
The Crest Hill pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Crest Hill 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 Crest Hill 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 Crest Hill, 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).
