Worst air pollution San Cristóbal, today and tomorrow

Today (16 July): Air quality in San Cristóbal is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 22.8/100).
Tomorrow (17 July 2026): Air quality in San Cristóbal is fair. PM10 increases to fair; O3 decreases to good; all other pollutants stay as today. Pollution peaks around 12:00 PM (PM10: 23.8/100). 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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San Cristóbal's air quality reflects the Chiapas Highland's Los Altos enclosed basin at 2,176 metres surrounded by the Altos de Chiapas ranges, with vehicle traffic on surrounding roads and the tourism, indigenous crafts, and government corridor contributing local sources. The basin's near-complete mountain enclosure creates severe concentration under winter inversions, while the elevated altitude worsens ozone formation and the wood-burning residential heating in this indigenous highland community generates elevated winter PM2.5 throughout the year.

Today - 16 July | Pollution peaks at 07:00

AQI:

Fair

22.8/100

PM2.5 (fine particles):

Good

14.8/100

PM10 (coarse particles):

Good

16.3/100

NO2 (nitrogen dioxide):

Good

3.8/100

O3 (ozone):

Fair

22.8/100

SO2 (sulfur dioxide):

Good

1.1/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

4.0/100

PM1 (ultrafine particles):

Good

8.0/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 12:00

AQI:

Fair

23.8/100

PM2.5 (fine particles):

Good

18.7/100

PM10 (coarse particles):

Fair

23.8/100

NO2 (nitrogen dioxide):

Good

2.9/100

O3 (ozone):

Good

19.6/100

SO2 (sulfur dioxide):

Good

0.8/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.9/100

PM1 (ultrafine particles):

Good

6.6/100

Frequently Asked Questions

Is air quality bad in San Cristóbal right now?

On 16 July 2026, overall air quality in San Cristóbal is fair. AQI is the main air quality indicator at 22.8/100. Pollution peaks around 7:00 AM (O3: 22.8/100).

Will air quality be worse tomorrow in San Cristóbal?

On 17 July 2026, air quality conditions in San Cristóbal will be similar to today, with AQI forecast at fair at 23.8/100. Pollution peaks around 12:00 PM (PM10: 23.8/100).

When is air pollution at its worst in San Cristóbal?

In San Cristóbal, traffic on the surrounding roads, charcoal and wood-burning, together with seasonal tourism traffic are the main local sources, with conditions worsening when calm, stagnant conditions settle in the surrounding valley. Topographic enclosure in the valley lets pollution accumulate rather than clear out. Photochemical reactions in the heat push ozone levels higher.

Are air quality levels in San Cristóbal 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.

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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 responsibility.

For long term forecasts and maps, see the Airmine app