Shanghai was moderately polluted on Sunday morning due to the approach of another cold front.

The main pollutant was PM2.5, with a concentration of 141 micrograms per cubic meter, and the air quality index was 188 at around 9am on Sunday morning, according the city's bureau of ecology and environment.

With the wind force increasing, the air quality improved to be slightly polluted in the afternoon.

Sunday was cloudy with temperatures fluctuating between 6 to 13 degrees Celsius.

From Sunday night to Monday morning, the wind force will gradually decrease with the concentration of PM2.5 increasing again. It is expected that the city will be slightly polluted in the short term.

The officials remind local residents to stay alert and reduce long-term, high-intensity outdoor exercise during the air polluted period, especially elderly people, patients with chronic diseases, children and those with weak immunity.

On Monday, with the arrival of wind from the north-east, the air quality index will improve to good or excellent, according to the bureau.

The temperature is predicted to keep dropping to between 4 and 11 degrees on Monday, to 4 and 7 degrees on Tuesday.

This year's second solar term in the Chinese traditional calendar, yushui, or Rain Water, fell on Sunday, which indicates the weather will get warmer and bring more precipitation in most areas of the country.