Data from the CHM15k (Figure 1) and the UMBC Micro-Pulse Lidar (Figure 2) at UMBC both support the presence of aerosols in the boundary layer throughout the day.
GOES-16 image (Figure 3) shows below 0.5 levels of Aerosol Optical Depth (AOD) in the middle of the day over much of the Continental United States and southern Canada, particularly in the central region. Clouds hindered a good AOD retrieval over Baltimore.
The EPA AIRNow Map shows Code Orange and Code Red for ozone levels in southern California for the day. This may be associated with high temperatures experienced in the region.