When it comes to weather people have a very short memory. I do distinctly remember that 5 years ago in Sydney we had a very wet and cool summer. I remember this because my wife (before we were married) stayed with me for the first time for a week and we had to use the heater at night in january. I also remember that the following winter (or perhaps it was the preceding one) we had a few days around 30 in june. It's nothing unusual in Sydney, not so common but not unusual. Probably the same all along the east coast.