Saturday will be this season’s third code orange air day, or air quality action day, meaning children, the elderly and those with heart and lung disease should avoid prolonged exposure outside.

Sunday and Monday will be code yellow days, meaning the air is OK, but unusually sensitive people, such as those with asthma or allergies, should avoid being outside for too long.

Ozone will be the main pollutant. Continued heat and humidity will affect air quality next week.