IMPORTANT: The air monitoring data used to calculate the Pollutant Standard Index ( PSI) report is taken from monitoring stations operated by Washington State Department of Ecology and PSAPCA. This is preliminary data and discretion should be exercised in its use.
Both Ecology and PSAPCA maintain extensive quality control and quality assurance programs to insure that strict precision and accuracy standards are met. Final validation of data occurs approximately 45-60 days after collection and is available from both Ecology and PSAPCA. Please contact an agency technical services staff member for more information about air quality data.
Updates to this web site are scheduled for weekdays before
10:30 a.m. PST. We offer daily updated air quality data.
These numbers reflect the highest Pollutant Standard Index for a specific
area during the previous 24-hour period. We also indicate which pollutant
is most prevalent for each location. This index is for the 24-hour
period ending every weekday at 8 a.m. PST. If we are experiencing an
air impairment episode (i.e. burn ban), we will update this site even on
weekends.