Climate outlook for June to August
Issued 26 May 2016
Climate outlook overview
- June to August rainfall outlook: above average for large parts of mainland Australia.
- Daytime temperature outlook: warmer than average for the tropical north and parts of southeast Australia; cooler in the southern mainland.
- Overnight temperature outlook: warmer than average for north and east.
- Climate influences include ENSO neutral/La Niña in the Pacific Ocean, neutral/negative Indian Ocean Dipole in the Indian Ocean and very warm sea surface temperatures surrounding northern and eastern Australia (see the Climate Influences section).
A wetter winter likely for most of Australia
- June to August (winter) rainfall is more likely to be above average across most of mainland Australia. However, southwest WA, southern Victoria, and most of Tasmania have roughly equal chances of a wetter or drier three months.
- Large parts of the country are more likely to have a wetter than average June. However, southwest Australia, southwest Victoria, and eastern NSW have roughly equal chances of a wetter or drier June.
- The current outlook reflects the combination of increasing odds for La Niña, chance of a negative Indian Ocean Dipole, and very warm sea surface temperatures surrounding northern and eastern Australia.
- Historical outlook accuracy for winter is moderate over southern WA, northeast Australia, and western Tasmania, with low accuracy elsewhere. See map for more detail.
Wetter outlook brings increased chance of cooler days for southern mainland Australia
- Cooler than average winter days are likely for most of the southern half of Australia. Warmer than average days are very likely (greater than 80% chance) for parts of the tropical north, southeast Victoria and all of Tasmania.
- Nights are strongly favoured to be warmer than average across northern and eastern Australia, including Tasmania, with a greater than 80% (or eight in ten) chance of warmer winter nights. Central Australia and southeast SA are more likely to have cooler than average nights.
- The current outlook reflects a combination of a potential La Niña event in the Pacific, increasing chance of a negative Indian Ocean Dipole, and very warm sea surface temperatures surrounding northern and eastern Australia.
- Historical maximum temperature accuracy for winter is moderate to high over most of Australia, except central WA and western SA. Minimum temperature accuracy is moderate to low for Australia.
- The tropical Pacific has now returned to neutral levels, marking the end of the 2015–16 El Niño. By July, the model suggests the Pacific may have reached borderline La Niña conditions, which is contributing towards the above average rainfall outlook.
- The breakdown period of the El Niño cycle typically sees warmer nights across much of Australia, and warmer days in the north.
- Sea surface temperatures across much of the Indian Ocean are above average, as well as waters surrounding northern and eastern Australia. These waters near Australian have warmed due to the breakdown of El Niño in recent months. The warmer waters in the Indian Ocean may provide extra moisture for rain-bearing systems as they cross Australia.
- Additionally, by the end of June, the model indicates an increased chance of a negative Indian Ocean Dipole. This typically brings above average rainfall to southern parts of Australia. However, this influence is likely to be off-set somewhat by a predicted increase in mean sea level pressure to the south of Australia, with southwest and southeast parts of Australia showing roughly equal chances of a wetter or drier three months.
- It should be noted that over the tropical north of Australia, it is seasonally dry at this time of year. The median rainfall at many tropical locations is between 0 and 1 mm for June to August, and even a small amount of rain would exceed the median.
- Bureau climatologists continually monitor the climate for any significant developments, with information on El Niño/La Niña and IOD events available fortnightly via the ENSO Wrap-Up. For a summary of Pacific and Indian Ocean outlooks, please see the Climate Model Summary.