In this study, recent spatial changes in climate were mapped since the turn of the 21^st century. The national SILO patch-point dataset for 4800 Australian Bureau of Meteorology climate stations was utilized. Thermal time, which drives plant development, was accumulated in the winter growing season between May-October and calculated as the summation of mean temperatures above a base of 5°C. Rainfall zones were defined by rainfall isoyhets and the ratio of summer to winter season rainfall.

Nationally, we found that rainfall zones were shifting towards the southwest since 2000 across Australia, except for Queensland where the shift in summer dominant rainfall was towards the southeast. In terms of May-October rainfall, the shift in rainfall was more towards the coast, so that isohyets moved more eastward in north-eastern Australia in contrast to more south-westward in south-west Western Australia. In terms of thermal time, there was also a southward shift, however this was more complex in signature. For example, in the Western Australian wheat-belt this shift was south-eastward in the northern wheatbelt, southward in the central wheatbelt, but in the far south there is a contraction from all directions in the region of coolest temperature. Further, annual rainfall variability is decreasing through much of the centre and northwest of the country, but increasing in other pockets.

When we focus on the Western Australian wheat-belt, we can see a similarity in the shift of a number of climate variables in some locations. For example, at Merredin, the thermal time, rainfall zones and May-October rainfall isoyhets all shift towards the southwest/west south-southwest by 125-150km. In this case, there is a basis to say that the climate of Corrigin is now very similar to the climate of Merredin in the previous century.