Changes in climate extremes over the Australian region and New Zealand during the twentieth century

Analyses of high quality data show that there have been some interesting recent changes in the incidence of some climate extremes in the Australian region and New Zealand. For the Australia region: the percentage area of Australia experiencing extreme wet conditions has increased slightly while the area of extreme dryness has reduced slightly since 1910 heavy rainfall has also increased in some areas during the same period, although not significantly the frequency of extreme warm days and nights has increased while extreme cool days and nights has decreased since 1961 a decrease in the total number of tropical cyclones since the late 1960s is largely explained by variations in the Fl Nino Southern Oscillation phenomenon while the number of stronger cyclones has increased slightly extratropical cyclonic activity has decreased over much of the mid-latitude waters south of Australia since the mid-1960s but increased at higher latitudes further southwest For New Zealand: warming from 1941 to 1990 has resulted in about 10 fewer days per year with temperatures less than 0 degrees C and around 2 more days per year greater than 30 degrees C in warmer locations the occurrence of moderate and severe drought decreased during the period 1951 to 1980 compared to the previous 30 year period changes in temperature extremes and drought frequency have been in response to changes in atmospheric circulation in the region.