Climate outlook for January to April 2021
Published Date: 24 Dec 2020
The Bureau of Meteorology has released the climate forecast from January to April 2021.
Climate outlook overview
- January to March rainfall is likely to be above average across much of the country, particularly in the eastern states, with strongest chances of above median rainfall in eastern Queensland.
- Maximum temperatures for January to March show little shift towards being above or below average for much of the country; the exception is in coastal regions and Tasmania where days are likely to be warmer than average.
- Minimum temperatures for January to March are very likely to be above average across much of Australia.
- La Niña and a positive phase of the Southern Annular Mode (SAM) are likely to be influencing the wet outlook, particularly for eastern Australia.
Wet start to 2021 for much of the country, particularly eastern Queensland
- January to March is likely to be wetter than average for much of Australia, particularly in the east. The chance of exceeding median rainfall is greater than 70% for much of Queensland and eastern parts of NSW and Victoria, increasing to 80% and above in eastern Queensland.
- For January, eastern Queensland, NSW, Victoria and Tasmania, as well as southern WA, have an increased chance (greater than 75%) of a wetter than average month.
- The fortnight 28 December to 10 January is likely to be wetter than average (chances exceeding 65%) in the east of the country and parts of southern WA, but drier in far western WA.
- While the outlooks indicate wetter than average conditions, southern parts of Australia are in their drier season, so rainfall (even if above average) is not likely to be sufficient to relieve long-term rainfall deficits.
Warmer days likely in coastal regions; warmer nights almost Australia-wide
- January to March days are likely to be warmer than average around much of the Australian coastline. Cooler days are more likely in southern WA.
- A similar pattern is likely during January although warmer than average days are also expected across part of the interior and SA.
- For the fortnight 28 December to 10 January, daytime temperatures are likely to be above average in western and central WA, western Tasmania, and the coastal strips of eastern Queensland and the NT's Top End. Below average daytime temperatures are likely in the south of the country and the eastern interior.
- Minimum temperatures for the first quarter of 2021 are likely to be above average for much of Australia (greater than 80% chance) except in southern WA and the southwestern half of SA where the chances are closer to 50%.
Maximum temperature maps
Minimum temperature maps
- La Niña remains active but is likely to be nearing its peak. Models suggest a return to neutral conditions (neither El Niño nor La Niña) by the end of the austral autumn.
- The Southern Annular Mode (SAM) is positive and likely to remain so over the 2020–21 summer. This typically enhances the La Niña wet signal in parts of eastern Australia but has a drying influence in western Tasmania.
- Warmer sea surface temperatures around much of the Australian coastline are likely to persist through the summer months, also influencing the wetter and warmer outlook.
- The Madden-Julian Oscillation (MJO) is now weak in the western Pacific after an active period in the Australian longitudes. It is likely to stay weak in the coming weeks but may strengthen in the Indian Ocean in January.
- The Indian Ocean Dipole (IOD) is neutral. The IOD typically does not impact Australian climate from December to April due to the seasonal position of the monsoon trough.
- Australia's temperature and rainfall variability are also influenced by global warming caused by human activities. Australia's climate has warmed by 1.44 ± 0.24 °C since 1910 while recent decades have seen increased rainfall during the northern wet season (October–April), with more high intensity and short duration rainfall events.
- The Bureau's climate model uses the physics of our atmosphere, oceans, ice, and land surface combined with millions of observations from satellites and on land and sea. As a result, it incorporates the influence of climate change and natural climate drivers like ENSO, IOD, the MJO, and SAM in its outlooks.