Today's Air Site
Air quality information is provided on TodaysAir.mt.gov. This site displays particulate concentrations and health effects for particulate matter less than 2.5 microns in diameter. This information is measured by monitoring equipment located throughout the state. The NowCast air quality concentrations are measured against health effect categories to provide a snapshot of the severity of impacts in your location. Concentrations are updated at 15 minutes past the hour at all stations. The most recent data displayed is the average particulate concentration measured over the previous hour.
For those counties with air quality programs using averaging times beyond the 1-hour average concentration of PM2.5 in issuing air quality alerts, an alternate data tool is under development which will address these data needs and is scheduled for release around the mid-December timeframe. Additional information regarding this tool will be provided in the near future. In the meantime, 1-hour average PM2.5 ambient monitoring data from all stations is available from Today’s Air or the Montana Data Portal for calculating longer average periods.