Fearsome threesome: how a trio of climate drivers is baking Australia’s west and leaving the east soaked

Western Australia has sweltered through higher-than-average temperatures due to the rare combination of three climate systems – El Niño, the Southern Annular Mode and the Indian Ocean dipole – hitting at once. Photograph: Dave Hunt/AAP

The Australian summer has been a tale of two extremes: the west is baking hot, while the east is awash with devastating downpours. While Western Australia’s maximum temperature so far this summer is 1.5C above the long-term 29.5C average, Perth has melted through three heatwaves and smashed February records for the most days hotter than 40C. Last month, the Pilbara town of Marble Bar sweltered through its second-longest hot spell on record, with 23 consecutive days above 43C.

In stark contrast, storms have ravaged the east coast this summer. Ex-Tropical Cyclone Jasper caused flooding across vast areas of far north Queensland before Christmas, delivering Australia’s wettest December days on record. One weather station recorded 1.9 metres of rain during five days.