Decatur pollen forecast - today, tomorrow and the week ahead
Today (16 July) pollen in Decatur is medium; grass is medium. Tomorrow (17 July 2026) levels are similar - grass declining. Over the following five days grass will decrease. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.
For long term forecasts and maps, see the Airmine app
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Use our Strava plugin to check your own exposure.
Decatur's central Illinois setting along the Sangamon River and Lake Decatur features oak, maple, and hickory as the main tree pollen sources, with the flat farmland and industrial river corridor shaping local exposure. Corn and soybean agriculture drive substantial ragweed and grass pollen in late summer, while the flat prairie terrain provides reasonable natural ventilation.
Today - 16 July
-
Alder (Alnus):
None
0/100
-
Birch (Betula):
None
0/100
-
Hazel (Corylus):
None
0/100
-
Cypress (Cupressaceae):
None
0/100
-
Grass (Poaceae):
Medium
31/100
-
Oak (Quercus):
None
0/100
-
Willow (Salicaceae):
None
0/100
-
Mugwort (Artemisia):
None
0/100
-
Ragweed (Ambrosia):
None
0/100
High pollen levels may trigger sneezing, itchy eyes, and congestion. Airmine's neighbourhood estimates use satellites to map local vegetation and a statistical prediction model, updated four times daily.
Tomorrow - 17 July
-
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
-
Oak (Quercus):
None
0/100
-
Willow (Salicaceae):
None
0/100
-
Mugwort (Artemisia):
None
0/100
-
Ragweed (Ambrosia):
None
0/100
Air quality in Decatur
View air qualityFrequently Asked Questions
Is pollen high in Decatur right now?
On 16 July 2026, overall pollen levels in Decatur are moderate. Grass is the main contributor to airborne pollen
Will pollen levels change in Decatur tomorrow?
On 17 July 2026, pollen conditions in Decatur will be different from today, with grass continuing to decline
Is pollen expected to decrease in Decatur this week?
According to the five-day outlook, grass pollen levels are expected to gradually decrease, while ambrosia pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in Decatur?
On 16 July 2026, Grass is the dominant pollen source in Decatur. cypress, oak, willow, alder, ambrosia, artemisia, and birch are not currently active.
When is pollen season in Decatur?
How often is the Decatur pollen forecast updated?
The Decatur pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Decatur 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 Decatur 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 Decatur, 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.
Want to see pollen forecasts for other cities in United States?
Check pollen in other popular cities:
Data provided by Airmine — Last update: 16 July 2026 at 05:36 CEST (Data is updated four times daily.)
This page provides the latest public pollen forecast for Decatur.
For long term forecasts and maps, see the Airmine app
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.