The pattern of seasonal maximum temperature odds across Australia is a result of
the combined effects from above average temperatures in the Indian Ocean
and cooler than average temperatures in the equatorial Pacific
Averaged over May to July, the chances are between 35 and 40% for above-normal
maximum temperatures in northeastern WA, much of the NT and Queensland, and
far northern NSW (see map). So for every ten years with ocean patterns like
the current, about six or seven May to July periods are expected to be cooler
than average over these parts of the country, with about
three or four being warmer.
Over the rest of the country, the chances of exceeding the three-month median maximum
temperature are mainly between 40 and 50%. So the chances of being cooler than normal are
about the same as the chances of being warmer.
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).
The neutral pattern of seasonal minimum temperature odds for the May to July period
in northern Australia (see map) is a result of effects from the Indian and Pacific Oceans
cancelling each other out: below normal minimum temperatures are promoted by the
La Niña pattern, while above-normal minimum temperatures are promoted by continuing
higher than average temperatures in eastern parts of the Indian Ocean.
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