Firefighters working to contain a dangerous bushfire threatening homes and lives north of Perth are bracing for scorching, windy weather.

The Red Gully blaze, which sparked on Saturday, has burned through some 9500 hectares in the Gingin and Dandaragan shires.

Crews were able to strengthen containment lines on Thursday but remain wary of windy weather into the evening and a hot Friday when the mercury is tipped to exceed 40 degrees.

“We’re confident in some of our containment lines but there’s a significant wind change coming in and that will put some pressure on,” incident controller Sven Andersen told reporters.

“(We’re) telling people to be aware that we’re not out of the woods yet. Hotspots could spot at any time.”

Soaring temperatures will create nightmare conditions for WA bushfire over next three days https://t.co/1v86XdAs6a

— ABC Perth (@abcperth) January 7, 2021

An emergency warning remained in place for some local communities on Thursday afternoon.

The greatest concern is held for residential estates at Ocean Farms Estate and nearby Seaview Park.

Residents who have already left are unable to return but may be granted special access on Friday.

“If that fire breaks out, it’s only an hour away from those estates,” Mr Andersen said.

He said the fire could turn “quite easily” in the right conditions.

Prepare for more hot days and uncomfortably warm nights across most of the WA coast and adjacent inland areas. Severe to extreme fire danger ratings are forecast for WA over the next few days, as are heatwave conditions. Check @dfes_wa and forecasts here https://t.co/k3BC8CexL0 pic.twitter.com/U5ed2crMeV

— Bureau of Meteorology, Western Australia (@BOM_WA) January 6, 2021

Nine national parks in the metropolitan Perth area have been temporarily closed due to severe fire danger in coming days.

“People camping or visiting WA’s national parks and attractions are being reminded to remain vigilant,” the state government said in a statement.

The Red Gully fire appeared under control late on Saturday but kicked up on Sunday.

08:25 PM -Bushfire EMERGENCY WARNING for parts of REGANS FORD, YATHROO, OCEAN FARMS ESTATE, SEAVIEW PARK, NILGEN, MIMEGARRA, KARAKIN, ORANGE SPRINGS in the SHIRES OF GINGIN and DANDARAGAN: https://t.co/ZSEIQCTb4B

— DFES (@dfes_wa) January 7, 2021

There have been no reports of homes being lost, but pine plantations, olive groves and some sheds are believed to have been damaged.

Some 200 firefighters are battling the blaze with the additional help of two large air tankers from Victoria.