AirNow reported moderate AQI levels over a wide area of the country. Ozone concentration turned from good to unhealthy levels for sensitive groups in the Plain States, Mississippi Valley and great lakes region throughout the day (top left). PM2.5 levels were moderate only in the Mississippi Valley. The great event continue being the fires and the large amount of smoke covering half of the nation (top right). According to HMS, light to moderately dense smoke remains situated across central North America. The smoke extends from southern Saskatchewan, Manitoba and Ontario, south through the Central Plains/Mississippi Valley, into Texas, Louisiana and Mississippi where it enters the Gulf of Mexico. The smoke also extends east through the Mississippi Valley into Tennessee, Mississippi, Alabama, Virginia, the Carolinas and Georgia. These areas likely consist of remnant smoke from the numerous large wildfires in the western US. True color image from Modis on Aqua detected fires and smoke plumes in Wyoming and Montana (middle left). High AOD levels were also detected in the Rocky Mountain States due to the fires mentioned (middle right). Lidar observations at Hampton University (Mid-Atlantic region) detected an aerosol layer at about 5km yesterday and today as indicated by Dr. Jia Su (bottom). The amount of aerosols have increased from yesterday as can be seen in the extinction coefficient at 1064 time series.