An email from Perth pointed out the plentiful mild weather lately. I see that Perth Airport 9021 is used in ACORN so I have had a look-see at all the raw monthly max data from CDO – (December data up to 16th so far). 
The first thing that hits me is a step-change coincident with the June 1994 install of a temperature probe (AWS). For larger version chart. Yet the BoM ACORN version for 9021 has no adjustment at 1994. The other point I would make is that UHI would have been steadily affecting this site as Perth housing & suburbia expanded producing warmer breezes. I can look at ACORN data later.
via Errors in IPCC climate science
December 17, 2021 at 05:28PM
Iowa Climate Science Education 