[viraptor]

Almost any place away from cities. I've got AQI <30, down to 5 or so, almost the whole year for example. (Apart from during an occasional bushfire)

Cities and industrial sites are the exception with bad air quality, not the default.

[vineyardmike]

To be fair, "cities are the exception with bad air" neglects the reality that cities are the default for where people live. So the "air near people" is generally city air.

That said, I live in SF and my AQI is usually <50. Not as great as 5, but we sometimes get down to single-digits. Cities don't have to have bad air.

[cyberax]

That depends, really. If you have an inversion layer going, you can get pretty poor air quality in lots of locations because people use crappy wood-fired stoves that produce a lot of particulates.

[20after4]

That does happen occasionally where I live, last night for example. But it's only a single digit number of days out of a year. The rest of the time air quality is very good.