The Murdoch press website PerthNow reports the Perth BoM pointing out that Perth has had another hot year. I also note how the BoM beats this up, “It’s an indication that Perth is warming and that is consistent with the whole of the South-West of WA and consistent with global temperatures as well,”.
Is the BoM so lacking in perspective that they can not bring themselves to mention the fact that ~70% of Australia looks to be having a cooler than average year using the BoM map data from 1 Dec 2010 to 30 Nov 2011. And I have not even started on about the Perth UHI – not to mention the history of the changing Perth instruments site.
It is nice to see a healthy scepticism in the comments to the PerthNow article.
Just a quick check of the BOM’s monthly summaries up to the end of November seems to show that Australia should have a mean average temperature of about -1.5C below the 1961-1990 average. With a cooler than normal December so far in most of the country we are on track to be the coldest year since 2000 (another La Nina year).
The National Tidal Centre has a number of modern tidal stations around Oz. One of them is at Hillarys Boat Harbour, some 16km N of the centre of Perth. Its thermometer has recorded a drop in temperature since 1991 equivalent to 0.6°C/century. Most of their stations around the coast are showing a similar decline, and a downtick in 2011. Several which show an overall increase, show a decline since 1999. I’m preparing a post with overall results to November 2011.
I see this article reporting on record hot days in the Pilbara.
Pilbara sizzles again after 49.4C – the hottest WA December day on record
Once again the heat is beaten up and you have to read very carefully down the text to see hints that earlier this month was not hot. In fact the vast majority of this month has been cool – and the month to date is below average.
Whenever we see or hear media about heat – we need to check the data to get the perspective.
Data from this useful site.