Sydney could get its best weather for the year, with a week of gently warming days, lots of sunshine and little rain.
Daily maximums in the city should be in the high-20s on most days and climb to 30 degrees or warmer over the weekend.
"The skies are as clear as they have been since early summer," Brett Dutschke, a senior meteorologist with Weatherzone, said.
Humidity will start to pick up later in the week but conditions, including for pollen counts, will be generally benign, he said.
Only a few millimetres of rain are expected in Sydney over the coming week - in sharp contrast to January, which brought the city's wettest start to a year since 1998.
Visitors streaming in from China should also appreciate the comparatively clear conditions. Pollution readings in Beijing on Monday varied from "hazardous" to "Beyond Index".
Big heat building up
Temperatures are less benign, though, in the far west of Australia, where Perth is expecting a string of very hot days.
The Western Australian capital may collect four days in a row of 40 degrees or warmer weather, the first such reading since February 1933, Mr Dutschke said.
Even if one of the days falls short of the 40-degree maximum, the four-day period starting on Monday should average 41 degrees on current forecasts. That would be the warmest spell in 18 years, he said.
While most of the heat will be contained in the west, some of it will make its way to eastern Australia. The Bureau of Meteorology is predicting an extreme heatwave for parts of Western Australia that usually bakes at this time of year but also a low-level heatwave for much of NSW.
The fire risks will be elevated in many inland regions, including in Victoria and NSW.
The most severe fire risks in the country's south-east, though, may be limited to a single day before a cool change expected to move through late this coming weekend, Mr Dutschke said.
Thursday is also forecast to have broadscale heat, with a large part of the country likely to experience 39-degree or warmer weather, the bureau said.
For Sydney, a cool change should bring a few cooler days from early next week before temperatures pick up again, Mr Dutschke said.
Weatherzone is owned by Fairfax Media, publisher of this website.
