The city has once again been covered in a thick haze after last night’s wind change, which blew smoke into the Sydney basin from bushfires across New South Wales, particularly the south-west.

Between 12pm and 1pm, Sydney’s eastern and south-west suburbs were worst affected. The Air Quality Index (AQI) dipped to hazardous levels – the east recorded an AQI of 320, while the south-west was at 365 – while the rest of the city was just at “unhealthy” levels. (Any reading over 300 constitutes “hazardous” pollution).

At the time of writing, that put Sydney at number 13 on a global list of cities with the worst air quality, as compiled by Swedish air purifier company IQAir. Canberra was ranked at 22, and Kolkata, India, number one.

The City of Sydney council has had to close all its outdoor pools (Andrew Boy Charlton, Prince Alfred Park Pool and Victoria Park Pool) and tennis courts for the day due to the unsafe levels of smoke in the air.

Follow the NSW Office of Environment and Heritage’s air quality alerts here.