Air quality in Mexico: where to check and what to do

Short answer. Check SINAICA, the national air quality information system run by INECC, which shows the daily AIRE Y SALUD index by state and real-time station data ¹. The index, set by standard NOM-172-SEMARNAT-2023, has five colour bands from Buena (green) to Extremadamente mala (purple) ². At "Muy mala" (red), people with heart or lung disease and over-60s should avoid moderate and vigorous outdoor activity ².

Where can I check air quality right now?

SINAICA, from the National Institute of Ecology and Climate Change (INECC), publishes the daily AIRE Y SALUD index for automatic and manual monitoring stations, selectable by state ¹. It also offers raw real-time data and validated data ¹. The measurements come from air monitoring systems run by state and municipal governments ¹, so coverage depends on where you live.

By law, each monitoring system must publish the AIRE Y SALUD index on its website and any other channel its authority sets ². The index shown is the worst one for each station ².

What do the index levels mean?

The AIRE Y SALUD index covers ozone, PM10, PM2.5, nitrogen dioxide, sulphur dioxide and carbon monoxide ². Each band has a colour and a health risk level ². The standard is mandatory for the state and municipal governments that run monitoring systems ². Particles are reported as a 12-hour weighted moving average, an approximation of the 24-hour mean used to warn people in time ². Thresholds for particles tightened in steps; the values below apply from January 2026 ².

For children under 12 and pregnant people, the standard advises reducing vigorous outdoor activity from "Mala", and at "Muy mala" reducing outdoor activity and preferably exercising indoors in a smoke-free space ². Its messages repeatedly advise seeing a doctor if symptoms appear and keeping informed about air quality ². See Air quality index explained.

How polluted is the air on average?

The population-weighted median of Mexican cities shows about 18 µg/m³ of PM2.5 (annual mean 2021-2023) ³, more than three times the WHO guideline of 5 µg/m³ ⁵. Nitrogen dioxide is about 12.7 µg/m³ ⁴, above the WHO guideline of 10 µg/m³ ⁵. That NO2 figure is a regional background over roughly 80 km: a busy street in a large city will be higher.

What should I do on a bad air day, or with smoke or dust?

On a bad air day, follow the AIRE Y SALUD advice for your group, given earlier on this page.

• Bad air days: follow the AIRE Y SALUD advice for your group above. See Pollution episodes, Sensitive people and polluted air and Children and polluted air.
• Ozone: the index uses the one-hour ozone average ². See Ozone days.
• Smoke: see Wildfire smoke, A clean-air room at home and Masks for smoke.
• Dust: see Dust storms.

Our Mexico alerts page explains how official warnings reach you. A household plan can note who at home is sensitive to polluted air and where to stay indoors.

Frequently asked questions

What does a red air quality level mean in Mexico?

"Muy mala", very high risk: people with heart or lung disease and over-60s should exercise only indoors in a smoke-free space ².

What PM2.5 level is "Buena"?

Below 15 µg/m³ as a 12-hour weighted moving average ².

Who measures air quality in Mexico?

State and municipal monitoring systems; INECC gathers their data in SINAICA ¹.

Is Mexico's air above the WHO guideline?

Yes for fine particles: about 18 µg/m³ of PM2.5 against 5 µg/m³ ³⁵.