U.S. Air Quality

Code Red PM2.5 Air Quality in Alaska from Wildfires; Code Orange Ozone in Northern California

Wildfires in Alaska are creating Code Red (Unhealthy) PM2.5 air quality conditions today. According to the Fairbanks Air Quality Program, which was the only source of current measurements that I could find for Alaska since the state does not participate in the AIRNow program, the 24 hour average of PM2.5 was 68.7μg/m³ as of 4:00 PM AKDT; yesterday's 24-hour average PM2.5 value was 13.0μg/m³, so conditions have deteriorated rapidly today. According to the National Interagency Fire Center, there are five fires burning in Alaska: two in the Fairbanks area, one in the Upper Yukon zone, one in the Kenai-Kodiak area, and one near Delta Junction. The National Weather Service has issued a Red Flag Warning for the Northern Alaska Interior this until midnight AKDT. A Red Flag Warning means that critical fire conditions are occurring now. Strong winds associated with the passage of a cold front are expected to increase the size of the fires, making it likely that the Unhealthy air quality will continue for the Fairbanks area tomorrow. Smoke from the fires is evident in today’s MODIS Aqua true color image for northeastern Alaska (courtesy of NASA MODIS Rapid Response), shown below overlaid with fire locations from NOAA’s Hazard Mapping System.

Elsewhere in the nation, ozone was in the Code Orange (Unhealthy for Sensitive Groups) range today in the Sacramento, CA, metropolitan region. PM2.5 levels continued to be Code Yellow (Moderate) across much of the Gulf Coast, Oklahoma, and southern California. Today’s loops of AQI values are below (PM2.5 on left, ozone on right; images courtesy of AIRNow).