Chengdu weather warning grade standard

The early warning of heavy pollution weather in Chengdu is divided into three levels, from low to high, yellow warning, orange warning and red warning.

Yellow warning: predict the concentration of PM2.5 >; 1 15 μ g/m3 lasts for more than 48 hours, and severe pollution occurs in a short time; Forecast daily average value of pollutants other than PM2.5 >: 200 will last for 48 hours or more, which does not meet the advanced warning conditions.

Orange warning: predict PM2.5 concentration >; 1 15 μ g/m3 will last for more than 72 hours and the concentration of PM2.5 >; 150 micrograms per cubic meter will last for more than 24 hours; It is predicted that the daily average of pollutants other than PM2.5 >: 200 will last for more than 72 hours.

Red warning: it is predicted that the daily average value of AQI > 200 will last for 96 hours and above, and the daily average value of AQI >: 300 will last for 48 hours and above; Or predict that AQI will reach 500 per day.