The pattern of seasonal temperature odds across Australia is due to recent higher
than average temperatures in tropical areas of both the Pacific and Indian Oceans,
with more influence coming from the Pacific.
Averaged over May to July, the chances are mainly between 60 and 70% for above-normal
maximum temperatures in the northern tropics and in western WA (see map).
So in years with ocean patterns like the current, about six or seven May to July
periods out of every ten are expected to be warmer than average in these
parts of Australia, with about two or three out of ten being cooler.
In contrast, the chances are between 35 and 40% for a warmer than average season
in southern Victoria and the southeast of SA. This means there's a 60 to 65% chance
of cooler than normal maximum temperatures averaged over May to July in these areas.
Outlook confidence is related to how consistently the Pacific and Indian
Oceans affect Australian temperatures. During the May to July period, history shows this
effect on maximum temperatures to be moderately consistent over large parts of the country,
but only weakly consistent in the southern half of Queensland (see background information).
Average seasonal minimum temperatures are favoured to be warmer than normal across
most of Australia's tropical regions, with the chances generally being between 60 and 70%.
In remaining areas the probabilities are in the neutral 45 to 60% range.
History shows the oceans' effect on minimum temperatures in the May to July period
to be moderately consistent over large parts of the country, with the exception of
SA and Victoria.