In the East, air quality was predominantly within moderate levels over the Mid-Atlantic and the Mississippi Valley as can be seen in AIRNow's animation below (left).
Peaks of code red were observed in the afternoon over North Dakota and also over Washington (right) where fires continue to be observed. HMS reported on smoke over the Pacific Northwest but not over North Dakota (bottom, left). A few fires were reported at the border between North Dakota and Canada, which means that the peak of PM2.5 that was observed over that region was most likely due to those fires.
MODIS Terra shows elevated AOD values over the Pacific Northwest, with larger values over some of the wildfires locations.