Following the activation of Phase I on December 25 due to Christmas fireworks and bonfires, Mexico State suspended the Atmospheric Environmental Contingency on December 26, 2025, as PM2.5 levels improved to acceptable ranges. The Alert Phase persists in Valle de Toluca and Santiago Tianguistenco due to ongoing pollutants, with normal Hoy No Circula rules in effect—no double restrictions.
The Government of Mexico State lifted Phase I of the contingency after stations in Xonacatlán (42 µg/m³) and Calimaya (37 µg/m³) recorded safer PM2.5 levels at 10:00 AM on December 26, aided by better weather dispersion.
Activated the previous day amid emissions from holiday celebrations and thermal inversion, the measure's short duration highlights rapid improvement. The Alert Phase now guides preventive actions in the Metropolitan Zones of Valle de Toluca (ZMVT) and Santiago Tianguistenco (ZMST): stay indoors if irritated, seek medical help for persistent symptoms.
Hoy No Circula resumes standard operation—no extra bans. On December 26, blue-sticker vehicles with plates ending in 9 or 0 are restricted from 5:00 AM to 10:00 PM. Exempt: hybrids, electrics, emergencies, verified public transport.
Authorities continue monitoring and advise emission cuts: no wood/fireworks burns, use efficient transport. Updates will follow air quality changes.