Annual climate summary Australia (2016): strong El Niño gives way to strong negative IOD.

Australian climate patterns and associated anomalies during 2016 are reviewed, with reference to relevant climate drivers for the Australian region. 2016 was the fourth-warmest year on record for Australia (annual anomaly of +0.87 °C), and the warmest year on record for the globe (the third year running that a new record has been set). Annual rainfall was above average for most of Australia, but below average for areas of the northern coasts between the Gascoyne in Western Australia and Townsville in Queensland, and pockets of coastal southeast Queensland and northeastern New South Wales.The very strong 2015–16 El Niño contributed to a very warm and dry first quarter. Autumn was the warmest on record nationally, with a significant nationwide heatwave occurring in late February to mid-March and bushfires at the start of the year in Victoria, Tasmania and Western Australia. In May the El Niño broke down and rainfall increased as a very strong negative Indian Ocean Dipole developed, lasting until November. While the central tropical Pacific approached La Niña thresholds during spring, a La Niña did not develop. The Southern Annual Mode commenced the year in a generally positive phase, was strongly positive in June and September, and was following by a strongly negative phase from late October until the end of the year.The period from May to September was record wet, relieving areas of drought in Queensland and southeastern Australia, but also causing flooding in multiple states. The last three months of the year saw a return to near-average rainfall and, while October and November were cooler than average for large areas, December was very warm for the eastern states.Ocean temperatures were also record warm for the Australian region during 2016, with an annual anomaly of +0.73 °C. Temperatures were particularly high during the first half of the year and resulted in widespread severe coral bleaching.