Air quality
Air quality in Flagstaff today
Updated
Good (US AQI 28) Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. Model estimate for Sun, Oct 25, 11:00 am (18:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Flagstaff, Arizona, United States, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 28 Good
- PM2.5
- 1.4 µg/m³ 0.1× WHO 24-h guideline
- PM10
- 2.8 µg/m³
- Ozone
- 101 µg/m³
- Dominant pollutant
- ozone sub-index 28
- Best hour today
- 11:00 am AQI 28
- European AQI
- 41
Air quality in Flagstaff right now
Right now the modelled US Air Quality Index for Flagstaff, Arizona, United States is 28, which falls in the "Good" band (up to 50). Air quality is satisfactory and poses little or no risk; a good time for outdoor activity.
The index is driven mainly by ozone, whose own sub-index is 28. Ozone usually peaks in the afternoon on sunny days and falls back after sunset.
PM2.5 is 1.4 µg/m³, within the WHO 24-hour guideline of 15 µg/m³; PM10 is 2.8 µg/m³ against a guideline of 45; ozone is 101 µg/m³ (above the WHO 8-hour level of 100); nitrogen dioxide is 0.4 µg/m³ (below the 24-hour guideline of 25).
Also this hour: UV index 5, carbon monoxide 107 µg/m³.
NASA FIRMS shows 3 fire hotspots within 300 km in the last day (nearest about 61 km), but particle levels are not elevated enough to point to smoke right now.
Flagstaff AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 28 around Sun 11:00 am to 46 around Sun 6:00 pm, staying "Good" throughout.
The following day looks similar, averaging about 41.
| Local time (America/Phoenix) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Sun 11:00 am | 28 | Good | 1.4 | 3 | 101 |
| Sun 2:00 pm | 38 | Good | 1.5 | 3 | 101 |
| Sun 5:00 pm | 45 | Good | 1.6 | 3 | 98 |
| Sun 8:00 pm | 44 | Good | 3.2 | 5 | 62 |
| Sun 11:00 pm | 38 | Good | 3.2 | 5 | 74 |
| Mon 2:00 am | 34 | Good | 2.8 | 5 | 84 |
| Mon 5:00 am | 36 | Good | 2.5 | 5 | 90 |
| Mon 8:00 am | 40 | Good | 2.7 | 4 | 84 |
| Mon 11:00 am | 41 | Good | 1.5 | 3 | 103 |
| Mon 2:00 pm | 44 | Good | 1.4 | 3 | 108 |
| Mon 5:00 pm | 48 | Good | 1.4 | 2 | 101 |
| Mon 8:00 pm | 47 | Good | 3.5 | 4 | 70 |
| Mon 11:00 pm | 40 | Good | 3.1 | 4 | 72 |
| Tue 2:00 am | 35 | Good | 2 | 3 | 83 |
| Tue 5:00 am | 36 | Good | 1.7 | 3 | 90 |
| Tue 8:00 am | 39 | Good | 2.5 | 3 | 84 |
| Tue 11:00 am | 41 | Good | 1.7 | 3 | 110 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Flagstaff today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 11:00 am (AQI 28, Good) and the worst around 6:00 pm (AQI 46). That is a swing of 18 points, so a run or walk around 11:00 am is noticeably better.
Flagstaff vs the rest of United States
Across 747 United States cities we track, the average US AQI right now is 48 (Good). Flagstaff at 28 is 20 points cleaner than average.
It ranks 77 of 747 from cleanest to most polluted; the cleanest is Aberdeen, SD (13) and the most polluted Springfield, PA (130).
For context, the median across 3,909 cities worldwide is 57.
Air quality in cities near Flagstaff
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Prescott | 104 km | 25 | Good | 1.6 |
| Fountain Hills | 177 km | 51 | Moderate | 7.8 |
| Surprise | 185 km | 48 | Good | 7.7 |
| Peoria | 188 km | 48 | Good | 7.7 |
| Scottsdale | 189 km | 51 | Moderate | 7.8 |
| Glendale | 191 km | 48 | Good | 7.7 |
| Mesa | 198 km | 51 | Moderate | 7.8 |
| Phoenix | 198 km | 51 | Moderate | 7.8 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Flagstaff, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Advice for sensitive groups
With the AQI at 28, there is no need for sensitive groups to change plans. People with asthma should still carry their reliever inhaler as usual.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Flagstaff
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS), NASA FIRMS.