Late-season heat may hit weekend sport and break temperature records across eastern Australia

Unusual late-season heat across much of eastern Australia may affect weekend sport and potentially challenge temperature records, forecasters say.

Sydney and Brisbane have already been sweltering through a couple of days of unseasonal warmth, straining power supplies on Thursday evening.

Those in the Queensland capital endured maximum temperatures that felt almost like 40C with humidity on both Thursday and Friday, Bureau of Meteorology data shows.

Melbourne was forecast to cop 37C on Saturday, potentially making it the hottest day this late in March for 16 years, the Weatherzone senior meteorologist Ben Domensino said on Friday afternoon.

Most of the summer had easterly winds, preventing much of the heat reaching the east coast. Those winds have now shifted to westerlies, bringing warmth that might catch people off guard.

Sydney is forecast to reach 30C on Saturday and 32C on Sunday. If reached, those temperatures would deliver the city its first run of four consecutive days of 30C or warmer in records that began in 1859.

The warmth will start to break down over eastern states by early next week. Still, with some heat sticking around over north-western and central Australia, there is the potential for another burst of heat towards the end of March. The mercury, though, is unlikely to climb as high as during the current heatwave, he said.

During El Niño years, normally easterly equatorial winds stall or even reverse, shifting rainfall eastwards and increasing the risk of heatwaves and dry conditions for much of Australia.