Seasonal climate summary for the southern hemisphere (summer 2017-18): an exceptionally warm season for Australia a short-lived and weak La Nina

This is a summary of the southern hemisphere atmospheric circulation patterns and meteorological indices for summer 2017-18; an account of seasonal rainfall and temperature for the Australian region is also provided. A short-lived and weak La Nina developed but decayed by the end of February 2018. Sea-surface temperatures were exceptionally warm in the Tasman Sea from late 2017 to early 2018. It was an exceptionally warm summer for Australia, and the third-warmest mean temperature on record for the nation. Summer rainfall was close to the long-term average for Australia, with above average rainfall in west and below-average rainfall in the east.