With no sport on, Sportsbet is offering various bets on the weather including warmest capital city and temperature over/unders. I suspect you could make a motza.
I wonder who they have employed to set the odds? Maybe some out of work meteorologists have a new job.
I suspect it would be a conflict of interest. I've previously seen one-offs like this in which the odds were badly out of kilter (although mostly of the variety of having things at odds of $26 which should be at odds of $26 million, e.g. Darwin as the coldest city).
One previous occasion I can remember is one of the bookmakers offering odds on over/under 42.5 degrees in Melbourne on what became Black Saturday, and I know quite a few people working in the field who had a piece of the overs.
A little insider trading perhaps?