This selection of data from the Central Slopes region details historical trends in extreme daily minimum and maximum temperatures and daily precipitation. It is designed to enhance NRM planning for climate change and is intended to supplement other reports from the Regional Natural Resource Management Planning for Climate Change Fund that detail the region’s climatology, climate drivers and climate change projections.   

The trends in extreme temperature indices are dominated by a strong, spatially consistent increasing trend in the temperatures of warm nights. The temperatures of warm and cool days are increasing: warm days faster than cool days. These effects are  stronger in winter than summer.

Also, the warm days and nights are warming at a rate greater than the cool day and nights.

Generally, most of the minimum temperature indices were changing at a greater rate than the maximum temperature indices.

Compared with the indices of temperature extremes, the changes in precipitation extremes between 1960 and 2010 are not as spatially coherent, nor are the trends as statistically significant. This is a commonly occurring feature in studies of precipitation extremes (Plummer et al. 1999, Suppiah and Hennessy 1998).

Caution needs to be exerted when comparing results from different studies on extremes, as the definition of indices frequently varies depending on the specific needs of stakeholders (as cautioned by other authors including Haylock and Nicholls 2000, Collins et al 2000).