Parts of NSW are forecast to reach the low 40s as several fires continue to burn across the state.

The Bureau of Meteorology is forecasting Sydney to reach 32 degrees Celsius on Sunday, while Penrith in the west is tipped to hit 40C and Richmond and Blacktown should reach 39C.

Parts of the lower and upper western regions are also forecast to hit 42C.

It comes after NSW sweltered through a hot Saturday, with more than 50 fires breaking out across the state.

A Watch and Act message was in place for the southeastern town of Berridale on Saturday night, with residents told to take action to protect themselves and their properties.

A fire at Craigs Road in the Southern Tablelands scorched more than 3689 hectares and destroyed property and livestock, while the Sandy Creek fire in the Upper Hunter burned through 26ha.

Canberra is expected to hit 36C on Sunday ahead of a cool change overnight bringing maximums in the low to mid-20s and the possibility of rain next week.

Meanwhile, Victoria is in for a cooler day after temperatures reached the high 30s and low 40s on Saturday. 

Residents along the Great Ocean Road in the state’s southwest were on high alert for much of the day, with a Watch and Act message in place for a blaze near Kenneth River.

Several other fires reached advice level before a cool change passed through the state on Saturday evening. 

Victorian temperatures should hover about the low to mid-20s for the rest of the week.

AAP, with Newstime Media