Monterrey air quality
Nuevo León, Mexico · Live AQI and hourly forecast for the next 5 days · updated Sat 18:00 local time
Good
Great air. A perfect time to be outside.
- Next 24 hours
- 22–45US AQI, highest around Sat 18:00
- Best time outside
- Sun 09:00–12:00US AQI about 22
- PM2.5 vs WHO guideline
- 0.2×3.7 µg/m³ over 24 h, guideline 15
- Cigarette equivalent
- ≈ 0.2 a dayBerkeley Earth rule of thumb
- European AQI
- Fairlevel 2 of 6
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Pollutants in Monterrey right now
| Pollutant | Now | Next 24 h vs WHO | US AQI band |
|---|---|---|---|
| Fine particles (PM2.5) | 3.0 µg/m³ | 0.2× | Good |
| Coarse particles (PM10) | 3.8 µg/m³ | 0.1× | Good |
| Nitrogen dioxide (NO2) | 4.5 µg/m³ | 0.2× | Good |
| Ozone (O3) | 82 µg/m³ | 1.0× | Good |
| Sulphur dioxide (SO2) | 2.4 µg/m³ | 0.1× | Good |
| Carbon monoxide (CO) | 216 µg/m³ | 0.0× | Good |
| Desert dust | 0 µg/m³ | ||
| Smoke and haze (aerosol optical depth) | 0.07 | ||
| UV index | 0.1 |
“Next 24 h vs WHO” compares the forecast with the World Health Organization’s 2021 guideline levels: 24-hour means of 15 µg/m³ for PM2.5, 45 for PM10, 25 for NO2, 40 for SO2 and 4 mg/m³ for CO, and 100 µg/m³ over 8 hours for ozone. Above 1× is above the guideline.
Next 48 hours
Hourly US AQI. Highest 48 around Sun 19:00, lowest 22 around Sun 10:00.
5-day air quality forecast for Monterrey
Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 150.
| Day | US AQI | At worst | PM2.5 avg | |
|---|---|---|---|---|
| Sat 26 Sept | 27–45 | 4.8 | ||
| Sun 27 Sept | 22–48 | 4.1 | ||
| Mon 28 Sept | 26–47 | 5.1 | ||
| Tue 29 Sept | 22–48 | 4.0 | ||
| Wed 30 Sept | 22–93 | 5.1 |
Common questions about the air in Monterrey
Is the air in Monterrey safe today?
Yes. Right now the US AQI in Monterrey is 45, which counts as good. Great air. A perfect time to be outside.
When is the best time to be outside in Monterrey?
Sun 09:00–12:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 22. The worst hour is around Sat 18:00, at 45.
What is the main pollutant in Monterrey?
Ozone (O3). It drives the index right now, at 82 µg/m³. Formed by sunlight acting on traffic and plant emissions. Highest on hot, still afternoons, often downwind of cities.
How does Monterrey's air compare with the WHO guideline?
Within the guideline. Over the next 24 hours PM2.5 averages about 3.7 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. O3 is forecast above its guideline level.
How many cigarettes is a day of Monterrey's air?
About 0.2 cigarettes. Over the next 24 hours PM2.5 averages about 3.7 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.
Will air quality in Monterrey improve this week?
Today looks cleanest. Its AQI peaks at 45, against 93 on Wednesday, the worst day in the forecast.
Measured near Monterrey
| Station | PM2.5 µg/m³ | Measured |
|---|---|---|
| Unnamed sensor Sensor.Community, low-cost sensor | 0.1 | Sat 18:38 |
Air quality near Monterrey
- Guadalajara 639 km SW
- Houston 665 km NE
- Mexico City 706 km S
- Dallas 859 km NE
- Phoenix 1,426 km NW
- Denver 1,622 km N
About this forecast
Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (10 km inside Europe), refreshed twice a day. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown; ground stations, where there are any nearby, show what monitors actually measure. The US AQI follows the US EPA scale and the European AQI the EEA bands. Readings for 25.69°N, 100.32°W, updated 2026-09-27 00:00 UTC.