Sydneysiders have woken to a blanket of smoke covering the city and its surrounds. Westerly winds have blown the smoke from the Gospers Mountain fire in the Hawkesbury region, where more than 140,000 hectares of bushland has burnt since it started last week. Sydney’s air quality is currently worse than that of notoriously polluted cities such as Bangkok, Shanghai and Chengdu.

Sydney’s north-west suburbs have been hardest hit. The measurement of fine air particles in suburbs around Rouse Hill and Richmond is more than 190 – safe air quality is anything below 66. Those fine particles can cause sore throats and nose and eye irritation. The haze will remain over the city until this afternoon, when a southerly change will help clear it. Residents of the north-west are advised to remain indoors and avoid exertion, and those with respiratory and lung conditions in other areas are also advised to avoid exercise and going outside.

The greater Sydney region is currently under a “severe” fire danger rating, and there is a total fire ban. This follows last Tuesday’s “catastrophic” fire danger – the first time Sydney has ever been placed under the highest-level warning.

New South Wales will also experience heatwave conditions this week, meaning it will have three or more days of abnormally hot temperatures. Temperatures in Sydney’s east are forecast to reach a high of 34 degrees today, while the west will experience highs of up to 39 degrees. The windy change is expected to exacerbate the bushfires, and no rainfall is expected.

Forty-eight bushfires are currently burning across the state, and 23 of those are uncontained. The Gospers Mountain fire north-west of Sydney and the Myall Creek Road fire in the far north of the state are the two biggest fires currently burning.

Keep up to date with Sydney’s air quality here.