started · updated
Valley of Mexico ozone contingency activated and then suspended
The Comisión Ambiental de la Megalópolis (CAMe) activated Phase 1 of an environmental contingency due to high ozone levels in the Valley of Mexico on Saturday, September 12, 2026. Monitoring stations recorded peak ozone concentrations of 161 ppb at Benito Juárez and 157 ppb at the Centro de Ciencias de la Atmósfera in Coyoacán.
The high levels were attributed to a high-pressure system, weak surface winds, and intense solar radiation, which prevented the dispersion of pollutants. As a result, extraordinary driving restrictions were implemented for Sunday, September 13, under the 'Hoy No Circula' program from 5:00 to 22:00 hours. Prohibited vehicles included those with hologram 2, hologram 1 with specific plate endings, and certain hologram 0/00 vehicles with pink stickers. Additionally, 50% of LP gas delivery units without dry disconnection valves and local/federal cargo vehicles faced specific time restrictions.
By 15:00 hours on Sunday, CAMe suspended the contingency as increased cloud cover and rising wind speeds improved air quality and pollutant dispersion. While the emergency measures were lifted, authorities noted that air quality remained poor in several areas of the metropolitan zone.
Entities
Benito Juárez · Ciudad de México · Comisión Ambiental de la Megalópolis · Coyoacán · Estado de México · Mexico City · Sistema de Monitoreo Atmosférico de la Ciudad de México · State of Mexico · Valle de México · Valley of Mexico
Claims
What the coverage asserts, and how many sources carry each claim.
- [● 17 SOURCES] Ozone concentrations reached 157 ppb at the Centro de Ciencias de la Atmósfera in Coyoacán. www.poresto.com · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · julioastillero.com · +6 more
- [● 19 SOURCES] A high-pressure system and weak surface winds contributed to atmospheric stability and pollutant accumulation. www.poresto.com · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · julioastillero.com · +7 more
- [● 7 SOURCES] Local and federal cargo vehicles face circulation restrictions between 6:00 and 10:00 hours. www.poresto.com · 889noticias.mx · lanigua.com.mx · codigoqro.mx · julioastillero.com
- [● 19 SOURCES] The Hoy No Circula program will apply on Sunday, September 13, from 5:00 to 22:00 hours. www.poresto.com · 889noticias.mx · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · +6 more
- [● 15 SOURCES] Authorities recommend avoiding outdoor activities between 13:00 and 19:00 hours. 889noticias.mx · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · noticias.imer.mx · +5 more
- [● 17 SOURCES] Ozone concentrations reached 161 ppb at the Benito Juárez station. www.poresto.com · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · julioastillero.com · +6 more
- [DISPUTED] CAMe activated Phase 1 of an environmental contingency due to high ozone levels in the Valley of Mexico. www.poresto.com · 889noticias.mx · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · +8 more
- [● 19 SOURCES] Private vehicles with verification hologram 2 and certain hologram 1 and 0/00 vehicles are prohibited from circulating. www.poresto.com · 889noticias.mx · www.diarioevolucion.com.mx · lanigua.com.mx · codigoqro.mx · +6 more