Sydney swelters through 30-degree Saturday

Sydneysiders are enduring another sweltering Saturday as thick smoke fills the air from an out-of-control fire burning dangerously close to homes in the city's south-west.

The temperature in the city reached 30 degrees by 2pm today, with northwesterly winds producing gusts of up to 25km/h later this afternoon.

The recent unseasonable heat expected to drop back to something more reasonable tomorrow, when a 25 degree top is forecast.

A haze of smoke swept over the Sydney Harbour yesterday.

There are reports of 30-feet flames crowning over trees as fire crews respond to a large bushfire at Casula that has spread to Holsworthy Army barracks.

The New South Wales Rural Fire Service earlier warned residual smoke from several hazard reductions burns underway may still be visible across northern parts of Sydney and the Southern Highlights throughout the weekend.

Controlled fires were yesterday lit in the Hornsby, Ku-ring-gai and Wollondilly shires yesterday, with strong winds carrying smoke across Sydney Harbour.

Sydney temperatures soared towards 35 degrees yesterday afternoon for the third time this week. Picture: Weatherzone.

Anybody with breathing problems is advised to stay inside until the smoke clears.

Meanwhile, parts of Victoria and South Australia are being lashed with wild winds and rain as a series of cold fronts sweep across the south-east.

Sydney is enduring more scorching weather today as an unseasonable April burst of heat continues to fry New South Wales.

The conditions could break more April weather records as the two-highest temperatures for the month were felt this week. Picture: AAP.

The city broke heat records again on Thursday – the maximum temperature of 34.6 degrees was the city’s second hottest April day on record.

The hottest ever - 35.4 degrees – was only registered on Monday.

By 7am yesterday morning before the sun had fully risen, temperatures in Sydney had already risen to 23 degrees.

A cold front is expected to cross into southern parts of the state this afternoon, with a cool change to sweep across the city tomorrow and drop temperatures to 25 degrees.

Sydney residents have been urged to take care under the sun as the temperatures skyrocket. Picture: AAP.

The unprecedented burst of heat also marked the first time on record that Sydney has registered two days over 34 degrees during April, according to data going back to 1859.

Earlier this week, parts of western Sydney also sweltered in temperature highs of 38 degrees, with Pooncarie reaching a record-breaking 40.5 degrees on Tuesday.