Lewiston, Idaho PM2.5 (fine particulate matter) AQI is 5 - Lewiston, Idaho PM10 (respirable particulate matter) AQI is 6 - Lewiston, Idaho NO2 (nitrogen dioxide) AQI is n/a - Lewiston, Idaho SO2 (sulfur dioxide) AQI is n/a - Lewiston, Idaho O3 (ozone) AQI is 2 - Lewiston, Idaho CO (carbon monoxide) AQI is n/a -