Geilo Trail Run (GTR 55k) - Pollen and Air Quality Forecast for Today
Pollen levels are high today, with cypress, grass, and willow as the main active species. Air quality along the route is fair. O3 (21.9/100) 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 53.7 km after start. Pollen exposure peaks at 49.4 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.
Geilo Trail Run 55k traverses the high Hardangervidda plateau and surrounding mountain landscape, where alpine grasses, dwarf birch, and crowberry are the main pollen sources. The season is extremely compressed at this elevation with birch peaking briefly through June at lower margins before alpine grasses contribute through July, while the open plateau means mountain winds frequently disperse pollen and snow can interrupt conditions at any point throughout this demanding high plateau trail event.
Today - 16 July
Pollen
Alder (Alnus):
None
0/100
Birch (Betula):
None
0/100
Hazel (Corylus):
None
0/100
Cypress (Cupressaceae):
High
59/100
Grass (Poaceae):
High
51/100
Willow (Salicaceae):
Low
20/100
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
8.3/100
PM10 (coarse particles):
Good
2.5/100
NO2 (nitrogen dioxide):
Good
0.9/100
O3 (ozone):
Fair
21.9/100
SO2 (sulfur dioxide):
Good
0.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.3/100
PM1 (ultrafine particles):
Good
9.4/100
Levels show the highest exposure along the full route
Other routes:
Frequently Asked Questions
Where is air quality worst on the Geilo Trail Run (GTR 55k) route?
Based on today's forecast, O3 is forecast at fair levels along the route today (21.9/100). Air quality is at its worst after 53.7 km into the route. Airmine calculates exposure at 200m intervals along the course using satellite-derived atmospheric data.
Where is pollen highest on the Geilo Trail Run (GTR 55k) course?
Pollen exposure peaks at km 49.4 today. This changes through the season as different pollen species become active.
When is pollen worst during the Geilo Trail Run (GTR 55k) season?
August coincides with peak cypress 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 Geilo Trail Run (GTR 55k) 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 Geilo Trail Run (GTR 55k), 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.