Daily weather extremes – maps and tables
Quickly see which areas had extreme temperature or rainfall
Climate Driver Update
Climate drivers in the Pacific, Indian and Southern oceans and the Tropics
Sea surface temperature maps
Sea surface temperature maps are not available for forecasts before Spring 2018
SST outlooks for the next 3 months
ENSO is the oscillation between El Niño and La Niña states in the Pacific region. El Niños typically produce drier seasons, and La Niñas drive wetter years, but the influence of each event varies, particularly in conjunction with other climate influences.
International climate model outlooks
The graphs are based on the ensemble mean for the most recent model run.
These graphs show the average forecast value of NINO3.4 for each international model surveyed for the selected calendar month. If the bars on the graph are approaching or exceeding the blue dashed line, there is an increased risk of La Niña. Similarly, if the bars on the graph are approaching or exceeding the red dashed line, there is an increased chance of El Niño.
Weekly sea surface temperatures
Graphs of the table values
Monthly sea surface temperatures
Graphs of the table values
5-day sub-surface temperatures
- See also: Links open in new window
- Animation of recent sub-surface temperature changes
- Archive of sub-surface temperature charts
Southern Oscillation Index
- Data Source: Links open in new window
- TAO/TRITON data
Cloudiness near the Date Line
About El Niño and La Niña (ENSO)
ENSO is the oscillation between El Niño and La Niña conditions.
The term El Niño refers to the extensive warming of the central and eastern tropical Pacific Ocean which leads to a major shift in weather patterns across the Pacific. This occurs every three to eight years and is associated with a weaker Walker Circulation (see diagram below) and drier conditions in eastern Australia. El Niño Southern Oscillation(ENSO) is the term used to describe the oscillation between the El Niño phase and the La Niña, or opposite, phase.
In the eastern Pacific, the northward flowing Humbolt current brings cooler water from the Southern Ocean to the tropics. Furthermore, along the equator, strong east to southeasterly Trade winds cause the ocean currents in the eastern Pacific to draw water from the deeper ocean towards the surface, helping to keep the surface cool. However in the far western Pacific there is no cool current, and weaker Trades mean that this "upwelling" effect is reduced. Hence waters in the western equatorial Pacific are able to warm more effectively under the influence of the tropical sun. This means that under "normal" conditions the western tropical Pacific is 8 to 10°C warmer than the eastern tropical Pacific. While the ocean surface north and northeast of Australia is typically 28 to 30°C or warmer, near South America the Pacific Ocean is close to 20°C. This warmer area of ocean is a source for convection and is associated with cloudiness and rainfall.
However, during El Niño years, the trade winds weaken and the central and eastern tropical Pacific warms up. This change in ocean temperature sees a shift in cloudiness and rainfall from the western to the central tropical Pacific Ocean.
The Southern Oscillation Index, or SOI, gives an indication of the development and intensity of El Niño or La Niña events in the Pacific Ocean. The SOI is calculated using the pressure differences between Tahiti and Darwin. The following figure demonstrates the typical fluctuations in SOI over a period of 11 years. Positive SOI values are shown in blue, with negative in orange. Sustained positive values are indicative of La Niña conditions, and sustained negative values indicative of El Niño conditions.
This graph shows the values of the SOI between 1991 and mid-2015. Monthly SOI data.
Each phase of the ENSO has a very different effect on the Australian climate. Events generally have an autumn to autumn pattern of evolution and decay. That is, they typically begin to develop during autumn, strengthen in winter/spring, then decay during summer and autumn of the following year. These effects are described in further detail on the following pages: El Niño and La Niña.
Further information about the El Niño Southern Oscillation and its impact on the Australian Climate.
The Climate Driver Update provides the latest information on the state of ENSO and the likely effect this will have on Australia.
Timeline of monthly Southern Oscillation Index (SOI) values since 1876
The Indian Ocean Dipole (IOD) is defined by the difference in sea surface temperatures between the eastern and western tropical Indian Ocean. A negative phase typically sees above average winter-spring rainfall in Australia, while a positive phase brings drier than average seasons.
International climate model outlooks
The graphs are based on the ensemble mean for the most recent model run.
Thse graphs show the average forecast value of the IOD index for each international model surveyed for the selected calendar month. If the majority of models are approaching or exceeding the blue dashed line, then there is an increased risk of a negative IOD event. If the majority of models are approaching or exceeding the red dashed line, then there is an increased risk of a positive IOD event.
About the Indian Ocean Dipole (IOD)
Indian Ocean sea surface temperatures impact rainfall and temperature patterns over Australia. Warmer than average sea surface temperatures can provide more moisture for frontal systems and lows crossing Australia.
Indian Ocean Dipole
Sustained changes in the difference between sea surface temperatures of the tropical western and eastern Indian Ocean are known as the Indian Ocean Dipole or IOD. The IOD is one of the key drivers of Australia's climate and can have a significant impact on agriculture. This is because events generally coincide with the winter crop growing season. The IOD has three phases: neutral, positive and negative. Events usually start around May or June, peak between August and October and then rapidly decay when the monsoon arrives in the southern hemisphere around the end of spring.
Indian Ocean Dipole years
The Southern Annular Mode, or SAM, refers to the north-south shift of rain-bearing westerly winds and weather systems in the Southern Ocean compared to the usual position.
Southern Annular Mode (SAM) history
About the Southern Annular Mode (SAM) outlook
The Southern Annular Mode can result in enhanced rainfall in regions of southern Australia.
The Southern Annular Mode, or SAM, also known as the Antarctic Oscillation (AAO), is a mode of variability which can affect rainfall in southern Australia. The SAM refers to the north/south movement of the strong westerly winds that dominate the middle to higher latitudes of the Southern Hemisphere. The belt of strong westerly winds in the Southern Hemisphere is also associated with the storm systems and cold fronts that move from west to east.
During the summer and autumn months (December through to May) the SAM is showing an increasing tendency to remain in a positive phase, with westerly winds contracted towards the south pole.
The contribution that the SAM makes to the climate variability in Australia and the apparent positive trend in the SAM are relatively recent discoveries and as such are still active areas of research.
The diagram above shows the area affected by the Southern Annular Mode, when it occurs and how long it may last.
In terms of mean sea level pressure, the SAM affects the coastal regions of southern Australia throughout the year. Extreme negative phases of the SAM can cause increased rainfall and cold air outbreaks in southern Australia.
Each SAM event, both positive and negative, tends to last for around ten days to two weeks. The time frame between positive and negative events however is quite random, but is typically in the range of a week to a few months.
The impact that the SAM has on rainfall varies greatly depending on season and region. If Australia were a few degrees further south, then the impact of changes in SAM would be much more pronounced. The diagram below describes the average impact on rainfall during a "positive" (westerly winds further south) SAM event.
The SAM also has an impact on temperatures. In general, in areas where rainfall is increased, temperature is decreased whilst where rainfall is decreased, temperature is increased.
The diagram above shows the impact that a "positive" SAM event (decreased westerly winds) has on Australian rainfall. Shading indicates daily rainfall anomaly in mm/day for each of the seasons. (Source: Hendon et al. 2007)
During July 2007, the SAM was in a strong negative phase. This was reflected in rainfall patterns across southern Australia.
- Have a look at the latest atmospheric circulation patterns.
- Current values of the Antarctic Oscillation Index (an index related to the strength and phase of the SAM) are available from the US National Weather Service (NOAA)
- The relationship between the SAM and Australian rainfall is discussed in detail in this research paper.
The Madden–Julian Oscillation (MJO) is the major fluctuation in tropical weather on weekly to monthly timescales. It can be characterised as an eastward moving 'pulse' of cloud and rainfall near the equator that typically recurs every 30 to 60 days.
Tropical Climate Update
MJO phase diagram
*Note: There are missing satellite observations from 16/3/1978 to 31/12/1978.
The MJO phase diagram illustrates the progression of the MJO through different phases, which generally coincide with locations along the equator around the globe. RMM1 and RMM2 are mathematical methods that combine cloud amount and winds at upper and lower levels of the atmosphere to provide a measure of the strength and location of the MJO. When the index is within the centre circle the MJO is considered weak, meaning it is difficult to discern using the RMM methods. Outside of this circle the index is stronger and will usually move in an anti-clockwise direction as the MJO moves from west to east. For convenience, we define 8 different MJO phases in this diagram.
Daily averaged OLR anomalies
Westerly wind anomalies
Time-longitude plots of daily averaged OLR anomalies (left) and 850 hPa (approximately 1.5 km above sea level) westerly wind anomalies (right) are useful for indicating the movement of the MJO.
How to read the Time-Longitude plots
The vertical axis represents time with the most distant past on the top and becoming more recent as you move down the chart. The Horizontal axis represents longitude.
Eastward movement of a strong MJO event would be seen as a diagonal line of violet (downward from left to right) in the OLR diagram, and a corresponding diagonal line of purple in the wind diagram. These diagonal lines would most likely fall between 60°E and 150°E and they would be repeated nearly every 1 to 2 months.
About the Madden–Julian Oscillation (MJO) outlook
The Madden-Julian Oscillation is associated with weekly to monthly periods of enhanced and suppressed rainfall over parts of Australia.
The Madden-Julian Oscillation (MJO) is a global-scale feature of the tropical atmosphere.
The MJO is the major fluctuation in tropical weather on weekly to monthly timescales. The MJO can be characterized as an eastward moving "pulse" of cloud and rainfall near the equator that typically recurs every 30 to 60 days. However, the signal of the MJO in the tropical atmosphere is not always present.
MJO effects are most evident over the Indian Ocean and western equatorial Pacific. It influences the timing, development and strength of the major global monsoon patterns, including the Indian and Australian monsoons.
Tropical cyclones are also more likely to develop in association with certain phases of a strong MJO event.
The MJO is associated with variations in wind, cloudiness, and rainfall. Most tropical rainfall comes from tall thunderstorms which have very cold tops. Thunderstorms that have cold tops emit only low levels of longwave radiation. Therefore, the MJO can be monitored by using satellite measurements of outgoing longwave radiation (OLR) to identify areas of cloudiness (low OLR) within the tropics.
The diagram above shows the area most affected by the Madden-Julian Oscillation (MJO), the seasons during which the MJO's influence on Australia is greatest, and for how long each active phase of the MJO typically lasts.
The MJO has its greatest effect on the tropical areas of Australia during summer. It may have some effect on parts of southern Australia, however this impact appears small when compared to the effect on northern regions, and remains the subject of research.
The MJO can have an effect on the timing and intensity of "active" monsoon periods in northern Australia. This can lead to enhanced rainfall - in both the intensity of the rainfall and the duration of the rainfall.
During late January 2006, an active phase of the MJO coincided with an active monsoon period, resulting in enhanced rainfall over northern Australia.
The following links provide further information on the MJO.
- The Tropical Climate Update provides information on the current phase of the MJO.
- Technical information and maps relating to the Real-time Multivariate MJO Index, which is a way of monitoring the climate and weather variations caused by the MJO. Please note that this product is a research product, and as such is not always updated and may be under-going continual changes as it is developed.
SSTs for April 2022 show cool SST anomalies across the central to eastern equatorial Pacific and along the coastline of South America, and mostly weak warm SST anomalies over parts of the Maritime Continent. Compared to March, cool anomalies in the central to eastern tropical Pacific have strengthened, while in the west SST anomalies are closer to average than they were during March.
Values of the three key NINO indices for April 2022 were: NINO3 −0.5 °C, NINO3.4 −0.7 °C, and NINO4 −0.6 °C.
Sea surface temperatures (SST) in the tropical Pacific Ocean for the week ending 8 May 2022 were cooler than average along and just south of the equator over most of the central and eastern Pacific Ocean, extending along the coastline of South America. Warm SST anomalies continue over parts of the southern Maritime Continent and around much of Australia. Compared to two weeks ago, cool anomalies in the tropics have strengthened in much of the area east of 160°W. Warm anomalies around northern Australia and the southern Maritime Continent remain similar to two weeks ago, and have weakened around the west of Australia.
The latest values of the three NINO indices for the week ending 8 May 2022 were: NINO3 −0.6 °C, NINO3.4 −0.8 °C, and NINO4 −0.5 °C.
Persistent NINO3 or NINO3.4 values cooler than −0.8 °C are typical of La Niña, while persistent values warmer than +0.8 °C typically indicate El Niño.
The 30-day Southern Oscillation Index (SOI) for the 30 days ending 8 May 2022 was +20.7. The 90-day SOI value was +14.2.
The 30-day SOI was persistently strong during April and remains firmly at La Niña levels. The 90-day value also continues to be typical of La Niña.
Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between +7 and −7 generally indicate neutral conditions.
Trade winds for the 5 days ending 8 May 2022 were slightly stronger than average over the central and western tropical Pacific. Trade winds have generally been stronger than average in recent months.
During La Niña there is a sustained strengthening of the trade winds across much of the tropical Pacific, while during El Niño there is a sustained weakening, or even reversal, of the trade winds.
The Madden–Julian Oscillation (MJO) has recently re-appeared in the western Indian Ocean. Climate models indicate the MJO is likely to briefly weaken, and restrengthen later this week over the Maritime Continent or western Pacific. Should the MJO re-strength in the Maritime Continent region, it can enhance rainfall in north-eastern Australia. It also typically increases cloudiness to Australia's north.
The Indian Ocean Dipole (IOD) is currently neutral. The latest IOD index value for the week ending 8 May 2022 was +0.13 °C. Surface waters are warmer than average over most of the Indian Ocean for the week ending 8 May 2022.
All five international climate models surveyed by the Bureau indicate a negative IOD event could develop by late autumn or early winter, with several forecasting strong negative values of the IOD index by August.
However, model outlooks issued at this time of year have low accuracy (skill) beyond autumn. The Bureau will continue to monitor model outlooks as winter approaches.
A negative IOD increases the chances of above average winter–spring rainfall for much of Australia.
Cloudiness near the Date Line has been consistently below average (positive OLR anomalies) since June 2021, and continues to be below average during early May 2022.
Equatorial cloudiness near the Date Line typically decreases during La Niña (positive OLR anomalies) and increases during El Niño (negative OLR anomalies).
The four-month sequence of equatorial Pacific sub-surface temperature anomalies (to April 2022) shows cool anomalies in the central and eastern tropical Pacific for April were generally weaker than those for March, despite an increase in spatial extent. For April, cool anomalies were present across most of the top 150 m of water from the International Date Line eastwards, reaching 2.5 °C to 3 °C cooler than average in some areas east of 140°W.
Warm anomalies continue west of the International Date Line, reaching 3.5 °C warmer than between around 100 m and 200 m below the surface. The distribution of warm anomalies in the western Pacific is similar to that during March, but the strength of anomalies has increased slightly.
For the five days ending 8 May 2022, sub-surface temperatures were 2 to 3 degrees warmer than average in the western equatorial Pacific between 125 m and 175 m depth in a region extending west from the International Date Line. Compared to two weeks ago, these warm anomalies have weakened.
In the east of the basin, cool anomalies have greatly reduced. Surface anomalies are currently focused just south of the equator (roughly within 0°S to 5°S), meaning it is possible that the narrower equatorial band sampled here (2°S to 2°N) may be missing stronger off-equatorial cool anomalies. See SST section for a map of present surface temperature anomalies.
The emergence and strengthening of warm anomalies in the sub-surface of the eastern equatorial Pacific typically foreshadow the breakdown of a La Niña event.
The 2021–22 La Niña continues in the tropical Pacific, with little change in strength in the past few weeks.
Several indicators of La Niña, including tropical Pacific sea surface temperatures, cloudiness near the Date Line, and the Southern Oscillation Index (SOI), have maintained or slightly increased their strength over the past fortnight. However, beneath the surface of the tropical Pacific, waters have warmed closer to neutral El Niño–Southern Oscillation (ENSO) levels.
Most climate models surveyed by the Bureau indicate a return to neutral ENSO by the early southern hemisphere winter. Only one of seven models continues La Niña conditions through the southern winter. La Niña conditions increase the chances of above average rainfall for much of eastern Australia, while neutral ENSO has little influence on rainfall patterns.
The Indian Ocean Dipole (IOD) is neutral. All climate model outlooks surveyed suggest a negative IOD may develop in the coming months. While model outlooks have low accuracy at this time of year and hence some caution should be taken with IOD outlooks beyond May, there is strong forecast consistency across international models. A negative IOD increases the chances of above average winter–spring rainfall for much of Australia. It also increases the chances of warmer days and nights for northern Australia.
The Southern Annular Mode (SAM) index is currently positive and is forecast to remain positive for the coming four weeks. During autumn SAM typically has a weaker influence on Australian rainfall, but as we approach winter, positive SAM often has a drying influence for parts of south-west and south-east Australia.
The Madden–Julian Oscillation (MJO) has recently strengthened in the western Indian Ocean. Most climate models indicate the MJO will briefly weaken, and then re-strengthen again later this week in the Maritime Continent or western Pacific region. Should the MJO re-strength in the Maritime Continent region, it can enhance rainfall in north-eastern Australia. It also typically increases cloudiness to Australia's north.
Climate change continues to influence Australian and global climate. Australia's climate has warmed by around 1.47 °C for the 1910–2020 period. Southern Australia has seen a reduction of 10–20% in cool season (April–October) rainfall in recent decades. There has also been a trend towards a greater proportion of rainfall from high intensity short duration rainfall events, especially across northern Australia.
The Southern Annular Mode (SAM) index is currently positive and is expected to remain mostly positive for the next four weeks. During autumn, SAM typically has a weaker influence on Australian rainfall, but as we approach winter, positive SAM often has a drying influence for parts of south-west and south-east Australia.
La Niña remains active in the tropical Pacific Ocean. While having shown signs of a slow decline over recent months, in the past fortnight this decline has stalled, and some indicators have strengthened again. Autumn is the usual time of the year in which ENSO events decay and return to neutral.
Most of the seven international climate models surveyed by the Bureau continue to indicate a return to neutral ENSO conditions (neither El Niño nor La Niña) by early winter. One model suggests La Niña values could persist throughout winter and into spring, but the majority maintain neutral-ENSO through to at least September.
La Niña increases the chance of above average rainfall across much of northern and eastern Australia during summer, with a weaker influence during autumn. Even in decline, La Niña can continue to influence global weather and climate.
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