An invasion of summerlike heat will be felt across parts of South Australia, Victoria and New South Wales early this week.
The setup for this unseasonable heat is high pressure near the Queensland coastline that will act to funnel warm, dry air from the interior of Australia southeast all the way to the coast of South Australia, Victoria and New South Wales.
While a brief shot of warmth reached Sydney during the middle of September, the warmth that is coming to Melbourne and Canberra will result in by far the highest temperatures since March.
Even the brief glimpses of heat that were felt in Sydney and Adelaide during the middle of September will be outdone by the heat expected from Sunday into the first half of next week.
The peak of the heat is expected in Adelaide on Sunday when the mercury reaches 32 C (90 F).
Melbourne and Canberra will feel the heat on Monday and Tuesday with temperatures near 32 C (90 F) in Melbourne and 29 C (85 F) in Canberra.
Normal high temperatures across the region are typically closer to 18 C (65 F) in early October.
Sydney will feel the heat Sunday from Tuesday when high temperatures range from 30-32 C (86-90 F).
A strong cold front will bring dramatically cooler air to all of southeast Australia during the middle of next week.