Climate outlook for May to August

Long-range forecast overview

• May to July maximum temperatures are very likely to be above median for most of Australia.
• May to July minimum temperatures are very likely to be above median for most of Australia.
• May to July maximum and minimum temperatures have a greater than 50% chance of being unusually warm for most of Australia.
• May to July rainfall is likely to very likely to be below median for parts of northern Australia and small areas of the southern mainland.
• The long-range forecast is influenced by several factors, including record-warm oceans globally and a decaying El Niño. For more details, see Climate influences.

Below median May to July rainfall likely for northern Australia

• May rainfall is likely to very likely (60% to greater than 80% chance) to be below median for most of Australia excluding parts of the east and western WA where there is an about equal chance of below and above median rainfall.
• May to July rainfall is likely to very likely (60% to greater than 80% chance) to be below median for most of northern Australia and small areas of southern Australia. Rainfall is likely (60 to 80% chance) to be above median for the western Gascoyne of WA, and scattered parts of eastern and central Australia. Much of the rest of Australia has about an equal chance of above and below median rainfall.
• For May, the chance of unusually low rainfall is above 50% for parts of northern WA, most of NT, and western Queensland. Unusually low rainfall is defined as the driest 20% of May to July periods from 1981 to 2018.
• For May to July the chance of unusually low rainfall is above 50% for parts of far northern Australia, although this is the dry season for that region. Unusually low rainfall is defined as the driest 20% of May to July periods from 1981 to 2018.

Warmer May to July days and nights likely to very likely for much of Australia

• For May, maximum temperatures are likely to very likely (60% to greater than 80% chance) to be above median for most of Australia except the Carpentaria and Daly districts of the NT.
• For May to July, maximum temperatures are very likely to be above median (greater than 80% chance) for most of Australia.
• For May, minimum temperatures are likely to very likely (60% to greater than 80% chance) to be above median for most of WA, Tasmania, the northern two-thirds of the NT, northern and eastern Queensland, eastern NSW, and southern and eastern Victoria.
• For May to July, minimum temperatures are likely to very likely (60% to greater than 80% chance) to be above median for Australia.
• For May, the western half of WA and parts of northern and eastern Queensland have at least a 50% chance of unusually high maximum temperatures. Unusually high maximum temperatures are defined as the warmest 20% of May to July nights from 1981 to 2018.
• For May to July, much of Australia except parts of northern NT and Queensland have at least a 50% chance of unusually high maximum temperatures. Unusually high maximum temperatures are defined as the warmest 20% of May to July days from 1981 to 2018.
• For May, unusually high minimum temperatures have at least a 50% chance of occurring for western and south-western WA, and parts of northern Queensland. Unusually high minimum temperatures are defined as the warmest 20% of May to July nights from 1981 to 2018.
• For May to July, much of Australia except central to southern parts have at least a 50% chance of unusually high minimum temperatures. Unusually high minimum temperatures are defined as the warmest 20% of May to July nights from 1981 to 2018.

Climate influences

The long-range forecast reflects known impacts from several significant climate influences:

• El Niño continues to decline and is near its end. Climate models indicate sea surface temperatures in the central tropical Pacific are expected to return to ENSO-neutral later in autumn 2024.
• Global sea surface temperatures (SSTs) have been the warmest on record for each month between April 2023 and March 2024. Notably, the Atlantic Ocean is showing exceptional and prolonged warmth in sea surface temperatures.
• Four out of seven international models are predicting a La Niña event by late winter; however, El Niño and La Niña predictions made in early autumn tend to have lower accuracy than predictions made at other times of the year. This means that current forecasts of the ENSO state beyond May should be used with caution.
• The Indian Ocean Dipole (IOD) is neutral. While the weekly IOD index value is above the positive threshold (+0.4 °C), this is due to record warm ocean temperatures in the north-west Indian Ocean. Sustained values above the positive threshold are required to confirm a positive IOD event is underway. IODs that influence Australian climate are typically unable to form between December and April due to the presence of monsoonal activity in the southern hemisphere.
• The Southern Annular Mode (SAM) is currently weakly positive. Forecasts indicate it will become neutral during the coming week. SAM typically has little influence on Australian rainfall patterns in autumn.
• A weakening pulse of the Madden–Julian Oscillation (MJO) has moved into the Maritime Continent. Most climate models indicate this pulse will become weak/indiscernible in the coming days. Widespread, enhanced tropical weather is unlikely to affect northern Australia in the coming fortnight.
• Australia's climate has warmed by 1.50 ± 0.23°C between 1910 and 2023, leading to an increase in the frequency of extreme heat events. In recent decades, there has been a shift to drier conditions across the south-west and south-east in the cooler season (April to October), due to a combination of natural variability on decadal timescales and changes in large-scale atmospheric circulation caused by an increase in greenhouse gas emissions.

The Bureau's climate model simulates the physics of atmospheric, oceanic, ice and land surface processes, and uses millions of observations from satellites as well as in-situ instrumentation on land and at sea. These simulations enable the model to account for the influence of climate change and natural climate drivers like ENSO, IOD, the Madden–Julian Oscillation (MJO) and SAM in its long-range forecasts.