Major power stations have left people without power as NSW residents continue to swelter through a heatwave, with temperatures tipped to reach up to 39C across parts of the state.

NSW Premier Chris Minns had asked businesses and homes to reduce energy use between 3pm and 8pm this evening as large-scale power shortages were expected across the state.

Some Sydney suburbs have already hit a scorching 37 degrees with even hotter temperatures to come as a heatwave grips two states. The heatwave has already struck western Sydney, with Penrith reaching 37 degrees at 1.

Australia’s biggest state looks to have narrowly avoided a widespread power break down, but only after residents, businesses and government employees took steps to “reduce demand”, the state’s energy minister has said.