Worst air pollution Flagstaff, today and tomorrow
Today (20 September): Air quality in Flagstaff is moderate. AQI, PM2.5, PM10, and NO2 are moderate; O3 is fair; SO2, CO, HCHO, and PM1 are good. Pollution peaks around 5:00 PM (NO2: 48.1/100).
Tomorrow (21 September 2026): Air quality in Flagstaff is moderate. PM2.5 decreases to fair; PM10 decreases to fair; O3 increases to moderate; all other pollutants stay as today. Pollution peaks around 4:00 PM (NO2: 56.2/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Flagstaff's air quality benefits from its elevated Colorado Plateau position at 2,106 metres, with clean Rocky Mountain and Colorado Plateau airflows providing generally excellent ventilation across this northern Arizona university city. Vehicle emissions from I-40 and US-89 are the primary local sources, while summer wildfire smoke from Arizona and New Mexico forests is an increasingly severe seasonal concern and winter wood-burning stoves contribute localised PM2.5 during cold nights.
Today - 20 September | Pollution peaks at 17:00
AQI:
Moderate
48.1/100
PM2.5 (fine particles):
Moderate
41.4/100
PM10 (coarse particles):
Moderate
42.1/100
NO2 (nitrogen dioxide):
Moderate
48.1/100
O3 (ozone):
Fair
30.1/100
SO2 (sulfur dioxide):
Good
2.2/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
2.3/100
PM1 (ultrafine particles):
Good
4.8/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 16:00
AQI:
Moderate
56.2/100
PM2.5 (fine particles):
Fair
38.6/100
PM10 (coarse particles):
Fair
22.6/100
NO2 (nitrogen dioxide):
Moderate
56.2/100
O3 (ozone):
Moderate
47.1/100
SO2 (sulfur dioxide):
Good
1.7/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
2.4/100
PM1 (ultrafine particles):
Good
4.5/100
Pollen forecast in Flagstaff
View pollen forecastAir quality forecasts for neighbourhoods and landmarks in Flagstaff
Frequently Asked Questions
Is air quality bad in Flagstaff right now?
On 20 September 2026, overall air quality in Flagstaff is moderate. AQI is the main air quality indicator at 48.1/100. Pollution peaks around 5:00 PM (NO2: 48.1/100).
Will air quality be worse tomorrow in Flagstaff?
On 21 September 2026, air quality conditions in Flagstaff will be similar to today, with AQI forecast at moderate at 56.2/100. Pollution peaks around 4:00 PM (NO2: 56.2/100).
When is air pollution at its worst in Flagstaff?
Seasonal changes shape air quality across Flagstaff: winter is generally the cleanest season, with cooler temperatures and less dust in the air, but spring dust storms and summer ozone together make March through September the toughest stretch. Monsoon storms in July and August can either clear the air with rain or stir up dust ahead of the storm front.
Are air quality levels in Flagstaff based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 20 September 2026 at 20:27 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 responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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