Mexico City’s AQI has been sitting at around 207 points for the entire day, which would warrant activating the enviromental ordinances if we followed the EPA’s measuring standard.
The EPA’s AQI considers pollution in one hour stages and in eight hour stages, if air quality is moderately bad for eight hours: You’ve got yourself a problem, but if it only hits a high peak during one hour... meh you’re OK.
Here, we use IMECA, which is own own standard, and while it foreshadows the American AQI, it has some differences, it has tougher standards on hourly Ozone, but it forgoes the eight hour stages.
In the end, the IMECA index today did not surpass the required 150 points (I suppose, 230-250 for American AQI) to trigger ordinances. People are freaking out about all the smog and the smell of smoke... but according to the government it’s something akin to sea fog.... in a city 2200m above sea level.
Several wildfires broke out around Mexico City lately, which would explain the smell of smoke according to the government. It would also explain why PM2.5 concentration has been very high for the entire weekend.
Not that I need to worry at all even if the ordinance is triggered, since I’m in the select group that has a car that is less than two years old, in the end it means that my twin turbo, two-ton car can drive, while something like a 2006 civic might not. This also applies to 3/4 ton suburbans that are 2018 MY or newer.