The new 24-hour forecast includes the Air Quality Index, the pollution level and the primary pollutant, and is available for three time periods during the day: 8 pm to 6 am; 6 am to 12 am; and 12 am to 8 pm.
The time divisions aim to provide more convenient information according to the daily bedtimes and outdoor schedules of residents.
The number of pollutants changes throughout the day according to weather conditions, said an expert from Shanghai Environmental Monitoring Center, local news portal eastday.com reported.
The expert said the air-quality forecast is still being tested, and it cannot be completely accurate, especially during heavy pollution. Local environmental protection departments will try to launch more detailed forecasts in different districts after more monitoring sites have been set up, the expert added.
New standards from the national authority will bring upgrades to the city's 10 air-quality monitoring points to detect six pollutants, including respirable suspended particles, particles with a diameter of 10 micrometers or less, and PM2.5 fine particles.
Meteorological authorities also started issuing air-pollution forecasts on the national level on Sunday, the China Meteorological Administration announced on Monday.
The National Meteorological Center, a department under the top weather administration, is in charge of the forecasts, which will use a six-grade scale, with the first grade meaning excellent air conditions.
Higher grade numbers mean conditions are less conducive to pollutants diffusing, spreading and disappearing, according to a statement from the administration on its official website.
Each day, the center will update forecasts for the coming 24 hours at 8 am and 8 pm.
The statement said that the move would assist the government and the meteorological authority in making policies in the event of major air pollution, while it will also give the public more convenient access to air pollution information.