Monday, 1 March 2021 - Seasonal Climate Summary for Western Australia - Product code IDCKGC21R0

Western Australia in summer 2020–21: wet and below average daytime temperature

Rainfall in summer was above average for north, east and along the west coast of Western Australia. Though tropical cyclone Joshua remained well offshore of WA coast, several well formed tropical lows produced widespread moderate to heavy rainfall along their passage. Seasonal mean maximum temperatures were above average along the north and west coasts of the state, in contrast to below average mean maxima over a large part of WA from the Southern Interior down and east of Albany. Mean minimum temperatures for summer were above average for the Pilbara, Gascoyne and western parts of the South west Land Division, while below average mean minima were confined in state's eastern interior.

Wet across north, east and west coast

• Western Australia's summer rainfall was nearly 50% above average, and it was the wettest summer since 2017–18.
• A number of well formed tropical lows resulted in above average summer rainfall in the state's north, east and along the west coast.
• The Gascoyne region was particularly wet largely due to a very wet period in early February and Dairy Creek in the inland north Gascoyne had its wettest summer in 90 years of record.
• During December, a number of tropical lows brought 3 to 4 times the December average rainfall to the state's north and east, including some record high December totals.
• A tropical low (02U) crossed the Pilbara coast west of Port Headland on 11 December then tracked across the interior and southeast, producing widespread moderate to heavy rainfall up to 160 mm along its passage; Noreena Down in the east Pilbara recorded 150.6 mm on the 12th, which was its highest summer daily rainfall in 102 years of record.
• A tropical low (03U) crossed the west Kimberley coast on 20 December and tracked south-east through the Kimberley to the Northern Territory; 5-day rainfall totals between the 20th and 24th were double their December average at sites in south-eastern parts of the Kimberley.
• A tropical low (08U) crossed far west Kimberley coast on 22 January then tracked through east Pilbara, and state's interior and south-east, and produced moderate rainfall to the Kimberley.
• A tropical low (12U) not only resulted in record wet February in the Gascoyne District, but also produced several highest summer daily rainfall on record along the west coast and south-west between the 6th and 8th as the low continued its southward journey.

Cooler days in the east and warmer nights in north-west

• Western Australia's summer mean maximum temperature was 0.53 °C below average and the coolest since 2005–06, and mean minimum temperature was 0.04 °C above average; coolest since 2016–17 for both.
• Very hot conditions were first observed along the Gascoyne coast on 21 December, expanding to the state's south and south-east till the 26th; many locations along the west coast experienced 3 to 4 consecutive days of 40 °C or above for a scorching Christmas Day and Boxing Day.
• A severe to low-intensity heatwave occurred in the north-west between 12 and 15 January; several sites recorded daily maximum temperatures over 45 °C with 47.1 °C at Roebourne Aero on the 14th the highest for this summer in WA; minimum temperatures of 33.2 °C at Paraburdoo Aero and Telfer Aero on the 15th were the state's equal highest minima for this summer.
• It was a very cool morning in the state's south-west, particularly around Perth on 1 December, with overnight temperatures dipping below 10 °C, Perth Metro and several other sites had their lowest summer temperature on record.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

Click on a map to show it full size in a pop-up window

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top