Home Air Quality Current Data - real time air quality information
Devils Gate Reservoir Restoration Project
*Current Value
Monitored Parameter 1-hr Average Units State Standard Federal Standard
Last date/time of values:
Note: *Preliminary data that has not been validated, which may affect hourly or daily average concentration.
*PM10 State and Fed standards are based on a 24-hour average
*PM2.5 Fed standard is based on a 24-hour average
*NO2 State Standard is based on 1-hour average
*BC no State or Fed standard
**BC sensor currently undergoing testing, data unavailable.
For information on the Region 8 – West San Gabriel Valley, which includes La Canada-Flintridge, Altadena, and Pasadena area, please click on the following link.
South Coast Air Quality Management District (AQMD) Air Quality Index (AQI) for Region 8 – West San Gabriel Valley (including La Canada-Flintridge, Altadena, and Pasadena area)
Air Quality Index Levels of Health Concern Numerical Value Meaning
Good0 to 50Air quality is considered satisfactory, and air pollution poses little or no risk.
Moderate51 to 100Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Unhealthy for Sensitive Groups101 to 150Members of sensitive groups may experience health effects. The general public is not likely to be affected.
Unhealthy151 to 200Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
Very Unhealthy 201 to 300Health alert: everyone may experience more serious health effects.
Hazardous301 to 500Health warnings of emergency conditions. The entire population is more likely to be affected.
Note: Values above 500 are considered Beyond the AQI.Follow recommendations for the "Hazardous category." Additional information on reducing exposure to extremely high levels of particle pollution is available here.

The AQI is divided into six categories:

Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:

  • "Good" AQI is 0 to 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
  • "Moderate" AQI is 51 to 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
  • "Unhealthy for Sensitive Groups" AQI is 101 to 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
  • "Unhealthy" AQI is 151 to 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects.
  • "Very Unhealthy" AQI is 201 to 300. This would trigger a health alert signifying that everyone may experience more serious health effects.
  • "Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected.

EPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on.