While New Zealand's been stuck under grey skies for a lot of this summer, things are heating up across the ditch. 

Temperatures are expected to reach the high 40s in the southern states of Victoria and South Australia.  

Some Australia Day events were cancelled yesterday out of safety concerns. 

Australian Correspondent Donna Demaio told Ryan Bridge it's the worst heat wave in decades.  

She says Dubbo has seen 46.1 degrees and 48 in an area called Noona, with some temperatures 21 degrees above average. 

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