Surface air temperatures have been increasing since records began in 1910 and particularly since 1960. Between 1910 and 2013, the average daily maximum temperatures in the Glenelg Hopkins region have increased by 1–1.1 °C. Daily minimum temperatures have increased by between 0.6–0.7 °C[i].

During the last decade the average annual number of days over 30 °C increased by three days, as did the number of days over 35 °C (by two days). However, unlike other regions in Victoria, the average number of frosts actually increased, by three days, and the number of cold nights (minimum temperature below 5 °C) increased by four per year. This may be a result of changes in cloud cover associated with the millennium drought[ii].

There has also been a decline in the region’s rainfall since the mid-1970s[iii]. There were wet years in the 1950s and 1970s followed by the millennium drought of the 1990s and 2000s. Seasonal trends in rainfall from 1901 to 2012 indicate small changes of less than 5 mm/decade. In general there was an increase in winter, spring and summer rainfall and a decrease in autumn rain. However, from 1960 to 2012 there was a consistent decrease in winter and spring rainfall[iv].  

These historical trends, model simulations of the climate response to greenhouse gas emissions and knowledge of the climate system formed the basis for the regional climate change projections[v].  The climate projections are not a forecast of the future climate. However, they do show plausible climate system responses to given greenhouse gas emission scenarios[vi]. 

 

[i] CSIRO, Climate change in Australia projections cluster report – southern slopes, CSIRO and Bureau of Meteorology, Australia, 2015.

[ii] Department of Sustainability and Environment, Climate change in the Glenelg Hopkins region, Department of Sustainability and Environment, Melbourne, 2008.

[iii] CSIRO, Climate change in Australia projections cluster report – southern slopes, CSIRO and Bureau of Meteorology, Australia, 2015.

[iv] CSIRO, Climate change in Australia projections cluster report – southern slopes, CSIRO and Bureau of Meteorology, Australia, 2015.

[v] CSIRO, Climate change in Australia projections cluster report – southern slopes, CSIRO and Bureau of Meteorology, Australia, 2015.

[vi] CSIRO, Climate change in Australia projections cluster report – southern slopes, CSIRO and Bureau of Meteorology, Australia, 2015.