SHANGHAI’S air reached severely polluted last night, its worst this year, as the city air quality index passed 300.

This followed three days of smog, though forecasters said the arrival of a cold front today with northeasterly winds should disperse pollutants.

Although yesterday was only January 11, it was the eighth polluted day of 2015, and saw the index peaking at 302 — in the highest pollution bracket — at 8pm.