Ozone levels (top, left), once again, reached code orange across most part of the Midwest, Northeast and southern California. PM2.5 levels (top, right) in those regions remained within the moderate range. For tomorrow, the five worst outlooks in terms of air quality are for Ann Harbor, Benton Harbor, Detroit and Flint, Michigan and also Chicago, Illinois. AIRNow forecast calls for Action Days in those cities.
In terms of fires, the smoke we see over Wyoming, Minnesota and the Great Lakes (left) are mostly from fires in Idaho and Montana, according to the HMS team. The smoke was optically thick, as we can see in the MODIS Terra AOD image below (right).