Boston Marathon - Pollen and Air Quality Forecast for Today
Pollen levels are low today, with grass as the main active species. PM2.5 levels along the route are low today at 2/100, well within safe limits for outdoor exercise. Based on Airmine's forecast, which uses satellite data to calculate exposure every 200 metres along the route, air quality is at its worst 41.0 km after start. Pollen exposure peaks at 23.6 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
The Boston Marathon takes place in spring, often coinciding with peak tree pollen season — particularly from oak, maple, and birch. Pollen levels can be high along the course, especially on dry days, while air quality is generally moderate but variable, influencing comfort over the full route.
Today - 25 June
Pollen
Alder (Alnus):
None
0/100
Birch (Betula):
None
0/100
Hazel (Corylus):
None
0/100
Cypress (Cupressaceae):
None
0/100
Grass (Poaceae):
Low
23/100
Willow (Salicaceae):
None
0/100
Oak (Quercus):
None
0/100
Air Quality
PM2.5 (fine particles):
Good
2.1/100
NO2 (nitrogen dioxide):
Good
1.4/100
O3 (ozone):
None
PM10 (coarse particles):
Good
0.9/100
SO2 (sulfur dioxide):
Good
0.2/100
CO (carbon monoxide):
Good
0.0/100
Levels show the highest exposure along the full route
Other routes:
Frequently Asked Questions
Where is air quality worst on the Boston Marathon route?
Based on today's forecast, Go3 levels are at their highest 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 Boston Marathon course?
Pollen exposure peaks at km 23.6 today. This changes through the season as different pollen species become active.
When is pollen worst during the Boston Marathon season?
April 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 Boston 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 Boston 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: 25 June 2026 at 00:00 CET (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.