The pattern of seasonal temperature odds across southeastern Australia is mostly a result
of a continued strong warming trend in the Indian Ocean, off the west coast of Western
Australia, and a warming trend in recent months in the equatorial Pacific.
Averaged over August to October, the chances are mainly between 60 and 75% for above average
maximum temperatures (see map). The chances increase to over 80% in most of northern NSW.
So in years with ocean patterns like the current, about six to eight August to October
periods out of every ten are expected to be warmer than average over southeastern Australia,
with about two to four out of ten being cooler.
Outlook confidence is related to how consistently the Pacific and Indian
Oceans affect Australian temperatures. During August to October, history shows
this effect on maximum temperatures to be moderately consistent across most of
central and northern NSW and the northern half of South Australia. However, over
far southern NSW, Victoria, the southern half of South Australia and most of Tasmania
confidence is only weakly consistent (see background information).
Average seasonal minimum temperatures are also favoured to be warmer than normal across
southeastern Australia (see map). The chances of increased overnight warmth (averaged over
the coming three months) are greatest in South Australia where most of the state has more
than a 75% chance of minimum temperatures above the median. The odds are slightly less in
NSW and Victoria but are still in the relatively high 70 to 75% range. Only in Tasmania
are probabilities significantly lower at 55 to 65%.
History shows the oceans' effect on minimum temperatures from August to October to be
moderately consistent over most of NSW, South Australia and SE Tasmania. However, over
parts of southern NSW, Victoria and NW Tasmania, the effect is generally only weakly consistent.
Click on the maps above for larger versions of the maps. Use the reload/refresh button to
ensure the latest forecast maps are displayed.