A crystal clear blue sky
Global warming? The pattern is well enough established. But even the Sydney Weather Bureau man on ABC radio today was surprised at the results for September.
Sydney's mean temperature for September was 2.75 degrees Celsius higher than any ever recorded for September. In fact it was hotter than the October long-term average.
Unfortunately, the Weather Bureau's office workers are closed for Labour Day holiday, so I cannot report the actual statistical analysis in written form. (They are on holidays, and haven't written it yet.)
This is based upon an ABC radio report only.