DIAGNOSE is software, written in MATLAB, to rapidly identify areas with “interesting” climate anomalies, use flexible averaging methods to produce a time-series of areal-average values of the climate variable of interest, and correlate this time-series with large-scale variables such as sea surface temperatures. The software uses gridded analyses of rainfall and maximum and minimum temperature across Australia. Time-series of totals, means, anomalies, or percentiles can be produced. The averaging methods included allow for continental averaging, state or catchment averaging, averaging over polygons with latitude & longitude specified, or over areas drawn freehand with a mouse. The database of gridded analyses is updated on the first day of the new month, to allow very rapid identification of interesting anomalies and the diagnosis of their possible causes. This allows rapid investigation of climate anomalies, for discussion with politicians, the media, and decision-makers affected by climate variations. We will demonstrate DIAGNOSE’s potential by discussing whatever interesting climate anomalies appear over Australia at the end of February 2002.