In the second holiday-related activation within a week, the Metropolitan Environmental Commission (CAMe) triggered phase 1 environmental contingency for PM2.5 particles in the southeast zone of Mexico Valley on January 1, 2026, following high pollution from New Year's fireworks and poor weather. Key areas like Iztapalapa and Nezahualcóyotl saw extremely bad air quality. The measure was suspended later that evening as conditions improved.
The activation came after elevated PM2.5 concentrations recorded at 9:00 a.m., with Iztapalapa stations rating air quality as 'extremely bad.' The Air and Health Index highlighted extreme health risks in Mexico City boroughs including Iztapalapa, Gustavo A. Madero, Benito Juárez, Cuauhtémoc, and Venustiano Carranza, plus State of Mexico municipalities like Nezahualcóyotl, Coacalco, and Tultitlán.
Pyrotechnics, bonfires, and waste burning during New Year's, coupled with poor ventilation, low winds, and thermal inversion from cold weather, drove the spike. By 11:00 a.m., Nezahualcóyotl matched Iztapalapa's extreme levels, prompting advice to avoid outdoor activities for children, seniors, and those with respiratory or heart conditions.
CAMe upheld the contingency at 3:00 p.m. due to persistent high PM2.5 in central and southeast zones but suspended it at 8:06 p.m. as air dispersed. The Hoy No Circula vehicle program ran normally without extras.
Officials urged no outdoor exercise, compliance with vehicle rules, no burning materials, and indoor stays for vulnerable groups. CAMe monitored closely, issuing updates as needed. This follows a similar Phase I activation on December 25, 2025, in Mexico State's Valle de Toluca area, underscoring recurring holiday pollution risks in the metropolitan region.
