Projected changes to extremely hot and extremely dry years in Australia Penny Whetton, CAWCR, Australia Percentage area experiencing an exceptionally hot or dry year: Southwest Western Australia Background The Australian Government is undertaking a Review of Drought Policy and asked CSIRO and the Bureau of Meteorology to prepare “An assessment of the impact of climate change on the nature and frequency of exceptional climatic events”. Recent observed trends and projected changes to temperature, precipitation and soil moisture were examined in terms of the historical 1 in 25 year event Seven regions were considered Results The areal extent and frequency of exceptionally hot years have been increasing over recent decades. Observed trends in exceptional dry years are less clear. Based on 13 simulations from the CMIP3 database over the period 2010-2040, years currently considered exceptionally hot are projected to occur every one to two years Years currently considered exceptionally dry are projected to occur over larger areas more often in the SW, SW WA and Vic& Tas regions, with little change in the other regions Policy relevance This study indicated that the existing 1 in 20-25 year trigger for exceptional circumstances drought support to farmers is not appropriate under a changing climate hot dry Observations Multi model means 10-90th %-ile range