The real-time air quality in California is 42 (GOOD) AQI now. This was last updated 4 hours ago .

The current concentration of PM2.5 in California is 9 (µg/m³). The World Health Organisation (WHO) recommends 15 µg/m³ as the threshold concentration of PM2.5 for 24 hrs mean. Currently, the concentration is 0.36 times the recommended limit.

Generally, the air quality at California starts deteriorating in late October. The winters are the worst-hit season in terms of air pollution.

You should wear a good N95 mask when you go outdoor in California until the AQI is improving upto moderate range.

Office going people should avoid personal vehicles and use public transportations or carpooling.

(i) The primary causes of outdoor air pollution are solid, liquid particles called aerosols & gase from vehicles emissions, construction activities, factories, burning stubble & fossil fuels and wildfire, etc.

(ii) Main causes of indoor air pollution are harmful gases from cooking fuels (such as wood, crop wastes, charcoal, coal and dung), damp, mould smoke, chemicals from cleaning materials, etc.

Indoor air pollution in California is as dangerous as outdoor pollution, because the air pollutants come inside the houses or buildings through doors, windows and ventilation.

In California, you must use an air purifier or fresh air machine at home or office indoor and close all the doors, windows and ventilations when the outdoor air quality index (aqi) in California is very high. Proper ventilation is highly recommended only when outdoor air quality is improving and moderate AQI range.