Impact of drought on temperature extremes in Melbourne, Australia

Melbourne, Australia, experienced a large increase in its maximum daily temperature on 7 February 2009. This new record was set after an extended period of drought. We test whether droughts tend to lead to increased daily maximum temperatures in Melbourne, relative to temperatures experienced after wet periods, separating this drought effect from the effect of synoptic-scale wind-flow on maximum temperatures. Data from 1957-2008 indicate that the daily maximum temperature is typically 1-3 degrees C higher after drought, relative to a similar synoptic situation after a wet period, in situations typically associated with high maximum temperatures (i.e. with winds from the north). When the wind is from the south (i.e. from over the sea) there is typically little or no difference between daily maximum temperatures after droughts or wet periods.