The pattern of seasonal temperature odds across Australia is a result
of recent warm conditions in the Indian Ocean and an increasing level
of warmth in the Pacific.
The chance that the average July-September maximum temperature will exceed the
long-term median maximum temperature ranges from 60 to 70% across most of WA, the
southern halves of both the NT and Queensland, northern SA and all but the
southern areas of NSW. In the southeast inland of Queensland the chance
This means that for every ten years with ocean patterns like the current, about six
or seven years would be expected to be warmer than average during the September
quarter over this broad zone stretching west-east across Australia, with about
three or four years being cooler.
The chances of a higher than normal seasonal average is between 50 and
60% in the far north, southern SA, southern NSW, Victoria and Tasmania.
Outlook confidence is related to how consistently the Pacific and Indian
Oceans affect Australian temperatures. During the September quarter,
history shows this effect on maximum temperatures to be moderately consistent
in WA, the NT, Queensland, northern and eastern NSW, and far northern Tasmania.
Elsewhere it is only weakly consistent (see background information). Therefore, this
outlook should be used with caution in western NSW and much of SA.
The outlook for mean minimum temperatures over July-September shows the
chance of a seasonal average above the long-term median minimum temperature is between
40 and 60% over most of the country. The only exception is across some
areas of inland southern WA where the probability of increased warmth
is between 60 and 65%.
History shows the oceans' effect on minimum temperatures in July to
September to be moderately consistent over Queensland and the east of the
NT, the southern half of WA, and parts of north and east NSW. Elsewhere the
effect is only weakly or very weakly consistent.