Desirable AQI, that is: Air Quality Index, is under 50, but conditionally okay up to 100. Guaranteed terrible for everyone is greater than 300. At the cottage, it’s been 500 for over 24 hours (this capture is from this morning), and 500 is the maximum on the scale. Color-wise, red, purple, and maroon are of escalating intensity, starting at 151. You can tell where the Canadian fires are, in the northwest of this map. If your northern North America geography is sketchy, that water in the north, and east of FireCentral, is Hudson Bay.