Yes. Here are some tips you can use to protect yourself when a particle counter or the air quality app data is not available.
1. The night sky turns a red color on polluted days.
2. Sunlight on polluted days turns a yellow or orange color. Clean sunlight is clear and white, almost colorless.
3. Air pollution makes clouds look fuzzy.
Click here to read the original article with comparison pictures: https://smartairfilters.com/en/blog/measure-air-pollution-look-at-night-sky/