As 2025 draws to a close, Guadalajara has registered an astonishing 220 days with air pollution so bad that it posed a threat to human health. Bad air days through December 11th were nearly five times higher than the same period in 2024.
Below, I’ll explain the top causes of all this pollution, where the worst cases occur, and what the city is doing about it.
Main Causes of Air Pollution in Guadalajara
The top pollutants in the city come from the following sources:
- Vehicles: Emissions from cars, motorcycles, and commercial trucks are a significant source of particulate matter and polluting gases. Road dust in certain areas is also a significant source of airborne pollution.
- Industrial emissions: Factories of various types emit pollutants into the air with minimal regulatory enforcement.
- Human activity: A range of activities contribute to air contamination, with three of the most common being field burning by farmers each winter following their harvests (it’s seen as a cheap and easy way to eliminate debris), extensive use of fireworks around the holidays, and accidental (or intentional) fires in public parks.
As in previous years, the worst air pollution in the metropolitan area for 2025 was recorded in the southern zone. For those who aren’t familiar, Guadalajara’s south side is relatively more afflicted with industrial emissions, traffic congestion reminiscent of Bangkok, unpaved roads, and far fewer trees than other parts of town.
Its lower elevation within the Atemajac Valley, combined with thermal inversions, also exacerbates the problem during the winter season. (Inversions happen when cold air is trapped under a layer of warm air, preventing the pollutants from dispersing.)
Collectively, these activities increase levels of PM10 and PM2.5 particles. These terms refer to the types of particulate matter (PM) in the air, based on their size.
PM10 particles can enter your lungs, whereas PM2.5 is so small it can pass into the bloodstream.
Impacts on Human Health
Guadalajara’s air pollution poses the greatest risk to inhabitants from PM2.5 particles.
These pollutants bypass the body’s front-line defenses, deeply penetrating the lungs and entering the bloodstream. PM2.5 is linked to strokes, heart disease, respiratory inflammation, and lung cancer. It also exacerbates asthma for those suffering from the condition.
For these reasons, experts recommend that residents wear a face mask when outside the home, avoid outdoor activities during primetime hours on days with hazardous conditions, close doors and windows in your home, and avoid automobile use as much as possible.
What is Guadalajara Doing to Combat Air Pollution?
The Ministry of Environment and Territorial Development (Semadet) is thus far taking a few modest actions to reduce polluting emissions during the upcoming winter season.
Notably, Semadet held meetings with municipalities across the state of Jalisco before the start of the winter season to request that they refrain from agricultural burning, burning of trash, or campfires. I would emphasize that these efforts are voluntary and hence, not highly likely to result in meaningful changes in private practices.
One exception to these soft asks is the government’s short-term ban on brickmaking activity from December 19 to January 3 to prevent the emission of pollutants during the peak holiday period.
SEMADET is also urging citizens to report any type of pollution, such as burning or bonfires, to its 911 hotline.
The local government is also working to improve urban tree cover. The Guadalajara Urban Tree Plan 2025 aims to plant 20,000 native trees, create green corridors, and remove concrete to create space for more planting. The plan prioritizes areas most affected by urban heat islands.
Researchers from the University of Guadalajara (UdeG) are very concerned with the city’s tepid response thus far to worsening air pollution. They warn that without stricter public policies, the city could face even more dangerous air conditions in the coming years.
How Guadalajara Monitors Air Quality Levels
The city’s air monitoring system consists of 13 stations distributed across five zones:
WEST: Aguilas and Vallarta
NORTH: Atemajac, Country, Santa Margarita, and Oblatos
CENTRAL: Oblatos
SOUTHEAST: Loma Dorada and Tlaquepaque
SOUTH: Las Pintas, Santa Fe, Santa Anita, and Miravalle
The monitoring stations located in the southern and eastern municipalities of San Pedro Tlaquepaque, Tlajomulco de Zúñiga, and El Salto usually record the highest levels of air pollutants in 2025, especially PM10 and PM2.5 particles.
Hermes Ulises Ramírez, an academic at the Institute of Astronomy and Meteorology of the University of Guadalajara, has called for improvements to the city’s monitoring stations, noting that some pollutants aren’t being measured at all, including lead and some pollutants emitted by hydrocarbons.
“The first eight stations, which are obsolete and located further inland within the Guadalajara Metropolitan Area, need to be replaced. Secondly, the number of stations in the network is no longer sufficient,” he recently told the El Informador newspaper.
He further asserted that Guadalajara’s environmental monitoring network overall needs better maintenance.
Beyond air monitoring, Ramírez also addresses the elephant in the room – Guadalajara’s significant issues with poor road infrastructure and auto congestion. What’s badly needed is more resources for road improvements to create smoother traffic flow, better coordinated traffic lights, staggered work schedules to reduce congestion, and better alternatives to automobile transportation.
To that list, I’ll toss in the need to eliminate topes (speed bumps) from numerous local roads, given their well-documented contribution to air pollution and road degradation. But I won’t hold my breath on that one, as I see more being added every year!
Ways to Monitor Air Quality in Your Area
For real-time air quality information, you can consult the official AIRE Jalisco website or the air quality index for Guadalajara on IQAir.