The pattern of seasonal temperature odds across southeast Australia is a result
of recent warm conditions in both the Pacific and Indian Oceans.
The chance that the average October-December maximum temperature will exceed the
long-term median maximum temperature, is above 70% across NSW, Tasmania, Victoria and most
of South Australia. Chances exceed 80% across nearly all of Victoria, some areas
in southern NSW and the southeast of SA.
This means that for every ten years with ocean patterns like the current, about seven
to nine would be expected to be warmer than average during October-December over most of
southeastern Australia, with about one to three years being cooler.
Outlook confidence is related to how consistently the Pacific and Indian
Oceans affect Australian temperatures. During October to December, history shows this
effect on maximum temperatures to be moderately consistent over much of northern and western
NSW, most of SA and the northern half of both Victoria and Tasmania. However, over a
large part of eastern NSW, southern Victoria and southern Tasmania confidence is only
weakly consistent, so this outlook needs to be used with caution in these areas (see background information).
The average minimum temperature for October to December is favoured to be
above the long-term median minimum temperature across the north of both SA and NSW (see map).
The chances of increased overnight warmth (averaged over the coming three months) in
these areas are mainly between 60 and 70%. The chances are between 50 and 60% over
remaining parts of the southeast.
History shows the oceans' effect on minimum temperatures during October to December to be
moderately consistent over most of SA, NSW and northwestern and southern Tasmania. However,
over most of Victoria, most of southeastern NSW, southeastern SA and central Tasmania the
effect is generally only weakly consistent.