Get the Facts
Frequently Asked Questions
Not always. Small particles of water vapor can scatter the light so thoroughly that the blue of the sky does not show through. This phenomenon is common in the South Bay during warm weather.
When air pollution levels are high, many residents experience some symptoms such as watery eyes, coughing, or wheezing. Even for healthy people, polluted air can cause respiratory irritation or breathing difficulties during exercise or outdoor activities. The effects generally depend on your current health status, the pollutant type and concentration, and the length of exposure to polluted air.
The people most susceptible to severe health problems from air pollution are:
- Individuals with heart or lung disease
- Individuals with respiratory problems such as asthma or emphysema
- Pregnant women
- Outdoor workers
- Children under age 14 whose lungs are still developing
- Elderly residents whose immune systems are weaker
- Athletes who exercise vigorously outdoors
The colors and letters used in the daily air quality report are based on the Air Quality Index. Green means good air quality, yellow is moderate, orange is unhealthy for sensitive groups.
You can find current and historical regional air monitoring data and meteorological data from the Air District’s air monitoring network on our website.
Last Updated: 2023/8/3