Seasonal Climate Outlook

Recent climate

March rainfall was above average for the South West Land Division (SWLD) due to a broad trough and a weak low pressure system producing thunderstorms and showers in early March.  Toodyay recorded 151 mm of rain in March.  Maximum temperatures in March were average to above average and minimum temperatures were above average.  Decile rainfall to date map from 1 January to 6 April indicates decile 8-10 rainfall for most of the SWLD.

Rainfall decile map for the South West Land Division for 1 January to 6 April 2021.

In March the atmospheric pressure was lower than normal over the SWLD.

Sea surface temperatures (SST) are warmer than average around much of the north, west and southeast of Australia. Warm SST anomalies to the west and northwest of Western Australia may be influencing local weather patterns.

The Southern Annular Mode (SAM), also known as the Antarctic Oscillation (AAO), describes the north–south movement of the westerly wind belt that circles Antarctica, dominating the middle to higher latitudes of the southern hemisphere. SAM is currently neutral and excepted to remain neutral throughout April. A neutral SAM has little influence on Australian rainfall. During autumn, SAM has less influence on rainfall than during other times of the year. For more information see the Bureau of Meteorology’s Climate Driver Update. 

The Indian Ocean Dipole (IOD) is neutral. Majority of models are indicating a negative IOD in July, but skill is low at this time of the year.

The La Nińa in the Pacific Ocean is now officially finished with most El Niño–Southern Oscillation (ENSO) indicators have now returned to neutral levels. Climate model outlooks suggest the Pacific will remain at neutral ENSO levels at least until the winter.

The table below summarises climate conditions over the past month and three-month periods, and can indicate what is likely to occur in the near future if climate conditions follow the current pattern.