Chicago Marathon - Pollen and Air Quality Forecast for Today
Pollen levels are low today, with grass as the main active species. Air quality along the route is fair. O3 (25.0/100) is fair. The remaining pollutants stay at good levels. Based on Airmine's forecast, which uses satellite data to calculate exposure every 200 metres along the route, air quality is at its worst 0.0 km after start. Pollen exposure peaks at 0.0 km after start.
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.
Chicago Marathon runs through the Chicago lakefront and city streets, with oak, maple, and elm as the main tree pollen sources encountered along the urban route. The October race date falls after the main grass and birch season, while mugwort from surrounding Illinois farmland can still contribute in early October and Lake Michigan onshore breezes can periodically disperse residual urban pollen throughout this flat iconic lakefront city marathon.
Today - 16 July
Pollen
Alder (Alnus):
None
0/100
Birch (Betula):
None
0/100
Hazel (Corylus):
None
0/100
Cypress (Cupressaceae):
None
0/100
Grass (Poaceae):
Low
14/100
Willow (Salicaceae):
None
0/100
Oak (Quercus):
None
0/100
Mugwort (Artemisia):
None
0/100
Mulberry (Morus):
None
0/100
Eucalyptus (Myrtaceae):
None
0/100
Plane (Platanus):
None
0/100
Nettle (Urtica):
None
0/100
Acacia (Acacia):
None
0/100
Ragweed (Ambrosia):
None
0/100
Air Quality
PM2.5 (fine particles):
Good
10.1/100
PM10 (coarse particles):
Good
8.7/100
NO2 (nitrogen dioxide):
Good
3.7/100
O3 (ozone):
Fair
25.0/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.5/100
PM1 (ultrafine particles):
Good
4.6/100
Levels show the highest exposure along the full route
Other routes:
Frequently Asked Questions
Where is air quality worst on the Chicago Marathon route?
Based on today's forecast, O3 is forecast at fair levels along the route today (25.0/100). Air quality is at its worst after 0.0 km into the route. Airmine calculates exposure at 200m intervals along the course using satellite-derived atmospheric data.
Where is pollen highest on the Chicago Marathon course?
Pollen exposure peaks at km 0.0 today. This changes through the season as different pollen species become active.
When is pollen worst during the Chicago Marathon season?
October coincides with peak grass season. Grass pollen typically rises in May-June.
How often is this forecast updated?
Updated four times daily. See the timestamp below for the most recent update.
Are pollen levels in Chicago Marathon 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 Chicago Marathon, 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.
Levels show the highest exposure along the full route. Airmine uses satellite data to calculate pollen and air quality every 200 metres along each race route, updated four times daily.
Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibiity.