Perth could be set for its mildest Christmas day weather in seven years, following record-breaking heat last festive period.
Meanwhile Australia's first tropical cyclone of the season, Darian, looks set to steer well clear of the WA coast.
With just six days until Santa arrives, the weather on the west coast is heating up, with low-intensity heatwave conditions forecast for Perth and localised parts of the west coast over the next few days.
But Bureau of Meteorology forecaster Jessica Lingard said a milder change would wash over Perth and most the popular holiday destinations by the big day.
"And that's due to a trough down the west coast making its way inland over the weekend," she said.
"So the hotter weather that we're experiencing this week being replaced by a nice cooler change."
Here's what Christmas Day looks like across the state:
'Beautiful' in Perth
Perth and the metropolitan area are forecast to reach up to 36 degrees in the lead up to Christmas, but by December 25 the heat will be stripped back significantly.
The city is expected to reach a sunny top of 30 degrees, with a balmy low of 19 at night.
That would make it Perth's lowest Christmas day maximum since 2015, when the top temperature was 28 degrees.
Ms Lingard said it would be a nice relief compared to last year, when Perth recorded its hottest Christmas Day ever at 42.8 degrees, followed by several days above 40.
"This year is looking beautiful and significantly cooler than the Christmases we've experienced in the last few years," she said.
If a beach trip is on the cards, you may want to arrive early.
Winds will start off moderate from the south to south-east during the morning, but the sea breeze could reach up to 40 kilometres per hour about the coastal fringe in the middle of day.
Mild in the south, warm in the east
Similar mild weather conditions will grace most of the popular holiday destinations across southern WA too.
Ms Lingard said they were expecting some cloud for far southern parts of the state, however.
"Temperatures will be in the low to mid 20s," she said.
"For most parts along the south coast, you could see a bit of cloud cover but there will still be some sunshine peeking through."
She said away from the south coast, it was looking sunnier and warmer.
Bunbury and Geraldton are expecting tops of 29 degrees while Esperance is tipped to hit 24 degrees.
The Goldfields and Central Wheatbelt, on the other hand, look set to sizzle under temperatures close to 40 degrees as the pool of hot air on the west coast moves inland.
"Northern parts of the Central Wheatbelt and through the Goldfields are actually going to experience quite a warm Christmas," she said.
"Kalgoorlie is heading for a temperature in the low 40s on Christmas Day."
Monsoon returns to the Kimberley
Meanwhile a Christmas wish is being granted to those in the Kimberley hoping for some relief from the heat.
Ms Lingard said peaks of the monsoon trough were heading toward Australia, and by Thursday it would be sitting "just north of the Northern Territory".
"So we will see much more increase in the thunderstorm activity through the Kimberley," she said.
"And that means that actually parts of the Kimberley are going for a relatively cool Christmas Day.
"Halls Creek is heading for a maximum temperature of just 29 degrees so it is actually going to be cooler in Halls Creek than it is in Perth on Christmas Day."
Ms Lingard said the Pilbara and far western Kimberley were likely to miss out on any significant downpours.
"We are still going to see some of those warm temperatures in the high 30s or low 40s," she said.
"But we should see an afternoon thunderstorm as well, so that might help cool things down through the afternoon."
Broome is expecting a top of 36 degrees, and Kununurra 30 degrees with the chance of a storm.
The imminent arrival of the monsoon trough comes as Australia's first tropical cyclone of the season has been declared.
Tropical Cyclone Darian is currently sitting west of the Cocos Island, but Ms Lingard said the system would steer well clear of the west coast.
"It would have to do some pretty impressive atmospheric gymnastics in order to reach us here on the mainland," she said.
While the seven day forecast gives a reasonable idea of the weather on the day, Ms Lingard said it was important to note there was still some uncertainty this far out.
"There's still an awful lot that can happen within the models in the environment to increase and introduce some changes to the forecast," she said.
"We are already seeing a slight increase in temperature forecasts north of Perth — Geraldton went out yesterday with a temperature forecast of 29 degrees and that looks like being up to 33 degrees now."
