Today was a very quiet day in terms of air quality in most of the US (AIRNow, left). The exception was once again the state of California, with moderate levels of PM2.5 persisting throughout the day. Code orange was observed in the LA region from early morning until the early afternoon. Haze in the San Joaquin Valley could be seen in MODIS Aqua images today (right).
In the Mid-Atlantic/Northeast area, moderate levels of PM2.5 were observed along the coast, from Philadelphia to New York in the afternoon.