Air quality results are in for the month of May, and according to the Northern Sierra Air Quality Management District (NSAQMD), there were no exceedances of the National Ambient Air Quality Standard (NAAQS) in particulate matter, identified as PM2.5, over the course of the month.
Typically, there aren’t any exceedances recorded this time of year, as usually indoor wood stove burning ends in May, and wildfire season has not yet begun.
The average daily PM2.5 value in May was 11.1 micrograms per cubic meter, based on the first 22 days of the month.
May was a wet month, with Portola receiving 3.13 inches over 12 days of measured precipitation, quite a bit higher than the 1.96 inches measured a year ago.
Since Jan. 1, the region has received above-normal precipitation, with much of the region at 150 percent. Normal temperatures and precipitation are expected through September.
Normal fire potential is expected through mid-July and above normal potential starting in late-July; at lower elevations, where there is a large crop of cured fine fuels from all of the rain, above normal significant fire potential begins later in June.
There also was an increase in tree mortality over the past year, per Northern California GACC, 6-1-19.