Climate outlook for June to August
Issued 17 May 2018
Climate outlook overview
- For the winter outlook, issued 17 May 2018, there is no strong indication that winter will be particularly wetter or drier than average for most of the country – the likelihood of exceeding median rainfall is near 50%.
- The exceptions are in western WA, where a drier season is more likely, and in the country's far southeast, where a wetter season is favoured.
- Both days and nights are likely to be warmer than average for winter in the south. Nights are favoured to be cooler than average in Queensland.
- Broad scale climate drivers, such as El Niño and La Niña and the Indian Ocean Dipole, are inactive (neutral), meaning they are currently having little influence on Australia's climate. Consequently, there is no strong shift in the outlook towards widespread wetter or drier conditions across most of Australia. See our blog on what to expect when climate drivers are neutral or weak.
- In the absence of major climate drivers, warmer than usual temperatures in the Tasman Sea and associated low pressure is likely to be having some influence on this outlook for winter. See the Climate Influences section for more information.
Dry winter likely for southwest Australia
- Overall, for most of the country there is no strong indication that winter will be particularly wetter or drier than average – the likelihood of exceeding median rainfall is near 50%.
- The exceptions are in western WA, where a drier season is more likely and in the southeast, where wetter than average conditions are favoured.
- For June, inland Victoria and NSW have a moderate chance of a dry start to winter, as does western WA.
- Historical outlook accuracy for winter is moderate to high over most of the NT, Queensland, northern NSW, western Tasmania and western WA. Elsewhere, accuracy is low to very low. See map for more detail.
Warmer than average winter likely in the south
- Both days and nights are likely to be warmer than average in the south.
- In Queensland, there is a moderate chance that nights will be cooler than average.
- Historical accuracy for winter maximum temperatures is moderate to high for most of the country except for inland sub-tropical WA and central and western SA where accuracy is low to very low. Minimum temperature accuracy during winter is generally moderate to high in most regions, apart from western NSW, southwest Queensland and the NT's Top End where accuracy is low.
Climate influences
- Broad scale climate drivers, such as El Niño and La Niña and the Indian Ocean Dipole (IOD) are inactive (neutral), meaning they are currently having little influence on Australia's climate. Therefore, there is no strong shift in the outlook towards widespread wetter or drier conditions across most of Australia. See our blog on what to expect when climate drivers are neutral or weak.
- When broad scale drivers are neutral, the climate is often influenced by more local effects, such as the ocean temperature immediately surrounding the continent. Warmer than average temperatures currently in the Tasman Sea and associated low pressure may act to bring more onshore wind and rainfall to eastern Victoria and northeast Tasmania. Westerly winds that flow across southern Australia at this time of year are also likely to be weaker – reducing the chance of rainfall in western WA.
- In addition to the natural drivers such as the El Niño–Southern Oscillation (ENSO) and the IOD, Australian climate patterns are being influenced by the long-term increasing trend in global air and ocean temperatures. This includes a resultant decline in May–June rainfall in southwest Australia since 1970, decline in April–October rainfall in the southeast since the mid-1990s, and a rainfall increase in parts of northern Australia since the 1970s.
- Bureau climatologists continually monitor the climate for any significant developments. See our ENSO Wrap-Up and Climate Model Summary for information and forecast of El Niño and La Niña and the IOD.
