Today (this morning) visibly the smoke is back and the smell is stronger than ever. This app (and its website) says that the current air quality is still only 50's aqi?! I cross-referenced with some Purple air sensors (aka community provided sensors), and the sensors near my house ...
Arlington Heights City of Chicago Communities & Primary Pollutant Arlington Heights Chicago www.airnow.gov/aqi/aqi-basics firesmoke.ca/forecasts/current O’Hare 3-Day Weather Observations (including visibility) Wikipedia Air Quality Index Wikipedia Particulates (including PM2.5) ...