Seasonal climate summary southern hemisphere (summer 2012–13): Australia's hottest summer on record and extreme east coast rainfall

Southern hemisphere circulation patterns and associated anomalies for austral summer 2012−13 are reviewed, with an emphasis on Pacific Basin climate indicators and Australian rainfall and temperature. Summer 2012−13 was a neutral ENSO period but saw an active burst of the Madden-Julian oscillation in January and February. The summer saw record-breaking temperatures across the country, with a widespread and persistent heatwave in January affecting all States and Territories and contributing to the warmest summer on record for Australia as a whole. Summer rainfall was below average Australia-wide, however extreme rainfall from tropical cyclone Oswald caused widespread record flooding in eastern Queensland and New South Wales at the end of January. In contrast, rainfall was below average in central and northern regions, particularly in the Northern Territory, due to the late onset of a weak Australian monsoon.