I was interested in this Sydney Morning Herald article with various statements about recent warm conditions in Sydney.
When you search for the headline – Cooler weather to mark start of winter – at the SMH website you get this intro text at the link –
“Another warm month makes the last 12 the hottest June-May stretch on record for Australia…think about that over the wet, cool weekend.” So I thought about that – take a look at the BoM map of maximum temperature anomalies for the 12 months ended 31st May. See that the highest ranking anomalies are in areas where the data is most scarce. Note that Alice Springs with data from ~1878 is the longest term station by far near these BoM high rank red anomalies. Checking Alice Springs history at this BoM site you need to copy and paste data for Alice Springs Post Office 15540 and then Alice Springs Airport 15590. Updating recent months from here.
You find that the 12 months ending 31 May 2013 averaged 30.6 – the 12 months ending 31 May 1881 averaged 30.8 – and the 12 months ending 31 May 1893 averaged 30.7. So I am left with the suspicion that if we had adequate historic data over Australia – then the statement – “Another warm month makes the last 12 the hottest June-May stretch on record for Australia…think about that over the wet, cool weekend.” – would be even harder to justify.
Any warmth in Autumn is at least partly due to the ever growing Urban Heat Island over Sydney. Rarely mentioned by the BoM and their supporters.
Another claim in the article – “Autumn registered only six days of days below 20 degrees…”. Attempts to paint Autumn as unusually warm – yet look at the BoM maps of maximum temperature anomalies for autumn – amazing anomalies of zero to 1 degree C. Near normal weather – what an utter non-event.