Fire crews continue to battle dangerous bushfires on the outskirts of Perth with conditions expected to intensify throughout the day.

Bushfire watch and act warnings were issued for Chittering, Bambung and Moondah to the city’s north on Sunday.

Residents were advised of a possible threat to lives amid concerns about changing conditions.

People not prepared to stay and defend their homes were told to leave immediately if the way was clear.

Several fires were also burning at advice level across WA, including near York east of Perth and at Marble Bar in the state’s northwest.

Homes and an RAAF base in Perth’s north were threatened on Saturday afternoon when fires broke containment lines amid intense heat.

The blaze broke out near the entrance to RAAF Base Gingin, a facility primarily used for pilot training.

It was one of four significant fires in the Wanneroo and Chittering areas, where temperatures cracked 41C shortly after 2pm.

The Bureau of Meteorology expected severe heatwave conditions to persist into the coming week over much of the state, including Perth and the rest of the southwest.

Perth is forecast to reach a maximum of 38C on Sunday, slightly cooler than the 40.7C recorded on Saturday.

It was the city’s first 40C day in almost two years.

Marble Bar, which topped 47C on Saturday, was predicted to reach a maximum of 46C, which would make it the Pilbara town’s 26th consecutive 43C-plus day.

Its record stands at 27 days in a row, set in early 2005.

- AAP