As part of the Great Salt Lake Summer Ozone Study, we have put together a summary of June Ozone statistics. This bar chart shows the number of stations that observed an 8-hour average over 75 ppb (in blue) and 65 ppb (in orange). The current EPA attainment standard is 75 ppb, but is expected to be lowered.
June ozone was highest during the hot weeks when a persistent ridge was camped out over Utah, giving us mostly clear skies and hotter than normal June summer days. Ozone pollution tended to clear out after rain events. As you can see, there several periods when ozone pollution was over the EPA's health standard. When the health standard is lowered, more days will be classified as unhealthy air. This will be a challenge for Utah and many places in the United States dealing with high ozone as they come up with strategies to improve air quality.