Following the phase 1 environmental alert issued over the weekend, Mexico City residents began the week on Monday with limitations on traffic and outdoor activities due to the high levels of ozone in the air.

In a Sunday evening press release, the Environmental Commission of the Megalopolis (CAMe) announced that at 5 p.m. on Sunday, the monitoring station in the borough of Miguel Hidalgo registered an ozone value of 134 parts per billion (ppb).

These conditions have led the CAMe to categorize the air in Mexico City and the metropolitan area as “bad to very bad,” representing a health risk ranging from “high to very high.”

Authorities expect that the high-pressure conditions will continue for much of the day with high temperatures, persistent solar radiation and very light winds.

It is also expected for these conditions to last until Tuesday.

The elevated “Hoy No Circula” (“no-drive days”) restrictions will remain in place until the alert is lifted. Cars with verification hologram type 1 and license plates ending in 1, 3, 5, 6, 7, and 9 are banned from circulation between 5 a.m. and 10 p.m. Also, cars with hologram type 2 are restricted, as well as those with hologram type 0 and 00, yellow tag and plate numbers ending in 5 and 6 (for full details, click here).

Although not restricted, outdoor activities are discouraged especially between 1 p.m. and 7 p.m., when ozone levels are more likely to be elevated. Authorities have also suggested avoiding the use of air fresheners, aerosols, paints, waterproofing and products that contain solvents.

Although Mexico City is used to alerts during pollution peaks, alerts in the fall are uncommon — they’re usually issued in the spring before the rainy season.

If a phase 2 alert is issued, in addition to the restrictions listed above, schools will be closed and all outdoor events and activities will be canceled. 

With reports from El Financiero, El País and Comisión Ambiental de la Megalópolis