@icanzilb How reliable is this? I always look at this map and see that only Barcelona and northern Italy are bad. How come other big cities are blue or green in Madrid, Germany, France or London, when they also have a ton of traffic? Is Barcelona’s traffic density so big compared to other major cities?

I also have an Awair Element, which might not be as precise, but it never shows crazy numbers for CO2 or PM2.5. Even in summer, with the window open in Eixample 🤷‍♂️