We had several days of smoke this season, with very little of it being from local fires. The following is a map of the CONUS showing the number of days with HMS smoke plumes from May-October 2017.
|Number of days with an HMS smoke plume for the period of May 1st - October 31st, 2017. Data from satepsanone.nesdis.noaa.gov.|
The maximum hourly concentration at the Fort Collins site was 106 ug/m3 and the maximum daily concentration was 60 ug/m3. (as a note, all PM data I show on this sites is from the real-time reports and have not been corrected or validated, meaning that these values may change). Both of these occurred on Labor Day (4th of September). You can read the blog post on that event here. This was the only day where the 24-hr concentration was greater than the EPA's standard of 35 ug/m3. However, as this was due to transported wildfire smoke, it will likely be classified as an exceptional event (which means it will be excluded when determining attainment status). Below is the time series of the 24-hour average PM2.5 concentrations in Fort Collins.
|Time series of PM2.5 concentrations in Fort Collins, CO from May through October 2017. Data from https://www.colorado.gov/airquality/.|
Some side thoughts: Environmental regulations have really helped improve air quality overall in the US. We have seen decreases in anthropogenic (meaning from human activity) emissions that have led to better "average" air quality. However, at the same time, we've also had lots more large wildfires that have produced extremely poor air quality for much of the western US. Reducing wildfire emissions is obviously difficult as it means stopping large wildfires before they start (land management, prescribed burns, people being more responsible, etc.). Thus, wildfire smoke is becoming an increasing health concern as it could be offsetting some of the air quality benefits gained from reductions in other emission sources. Know how to protect your health during smoke events and stay aware of current air quality conditions!