This sequences of screenshots displays official PM2.5 readings for the eastern half of North America over an 11-day period beginning December 22, 2024. It was captured as screenshots from the US EPA AirNow Interactive Map of Air Quality.

What I have gleaned from viewing this map every morning for more than a year is that there is a distinct pattern in Kingston’s unhealthy PM2.5 readings. As documented in the Evidence page on this site, virtually all of those airborne pollutants originate far away rather than from any local or even regional sources, and correlate with southerly wind directions which means that they are coming from US sources.  Also on that page, they lack of any real time-of-day or day-of-the-week correlation with hourly Kingston readings implies that the source is heavy industry rather than housing, transport or small business emissions.  

The actual pattern is