Overview
- CAMe activated Phase 1 in the morning after a PM2.5 reading of 107.3 µg/m³ at the Santiago Acahualtepec station in Iztapalapa at 08:00.
- The regional action covered four CDMX boroughs—Iztapalapa, Milpa Alta, Tláhuac and Xochimilco—and 13 municipalities in the State of Mexico.
- Authorities attributed the hazardous concentrations to widespread New Year pyrotechnics and burning, compounded by thermal inversion, low temperatures and weak winds.
- Phase 1 measures included public health advisories, bans on open burning, a 40% cut to industrial particle emissions, and suspensions of construction and certain combustion activities.
- CAMe maintained the contingency through the afternoon update and suspended it at 20:00 as most stations showed acceptable or good PM2.5 levels; Hoy No Circula operated under normal rules without a 'Doble' activation.