Category Archives: Urban Heat Islands

BoM fiddling Goulburn minimum temperature 2nd July 2017 reveals extent of errors in BoM AWAP temperature maps

Minus 10.4 degrees C was recorded originally at GOULBURN AIRPORT AWS (070330) which was filed by blogger Lance who noticed the BoM rapidly altered this to -10. Jennifer Marohasy blogged on the issue 4 July and passed the info on to a journalist who asked the BoM if they could explain. BoM said they have a “QC” auto function clipping off extremes in case there are errors. And this caused the reset to -10°. JM blogs again on 5 July. This revelation of raw data trimmimg is brand new to many of us who monitor BoM data – but OK thats what the BoM says happened. Jo Nova is also onto the issue. Lance and I checked BoM AWAP maps for NSW daily minimum temperature and noticed the contouring was hugely in error when checked against actual minimums. I have NSW daily minimum temperature maps offline for the 1st July – 2nd July and 3rd July. Just looking at data from the Southern Tablelands region (the white O circles the Goulburn and Canberra localities.) Goulburn is in the wrong contour zone all 3 days. Canberra Airport should be well into the -6 to -9 zone on all 3 days – yet it is always plotted on the boundary of the -3 to -6 and -6 to -9 zones. Always wrong. Taralga about 40km NNE of Goulburn (approx marked white T) read -7° on the 1st & 2nd yet the correct -6 to -9 degrees zone boundary is way too far west on those days. Yass recorded -8.7 on the 2nd yet the contouring has Yass in the next warmer zone. Likewise Cooma on the 3rd should be in the -6 to -9 zone but is shown in the next warmer zone. I expect readers might find errors in other parts of the State – or in other States
With so many errors I wonder what purpose these maps can be fit for. On the issue of the BoM clipping sub -10° readings back to an even -10. Lance mentioned to me these very cold reading from Goulburn Aero Club 70210 in July 1971 – down to -13.9°. Cop that 14 days of frosts in 1971!! Worth noting too the all time coldest Canberra Airport min was -10 on 11 Jul 1971. So setting -10 as an alarm was somewhat odd and without sound scientific foundations – but Hey!! it is the BoM.

New BoM Adelaide West Terrace site warmer at night than Kent Town

I blogged over two years ago on the BoM moving their main Adelaide weather instruments site from Kent Town to West Terrace not far from where the site was from the 1800’s up to 1979. In April 2015 I said – Bureau of Meteorology delusions about the urban heat island revealed in news of relocation (again) of Adelaide weather instruments – And now we see West Terrace is starting its new life warmer at night than Kent Town – assuming the BoM have had time to iron out any instrument faults – there is a gap of 4 hours at West Terrace on the 15th. If readers wanted to do any night time vehicle/temperature traverses – data might be interesting.

Link for larger chart

BoM trumpets January the warmest month on record for Sydney

The BoM blah-blahs on – Every station in the metropolitan area recorded its highest January mean temperature on record and most stations (including Sydney Observatory Hill) also broke records for mean maximum and minimum temperatures.
Not a word on the above BoM page of the ever growing urban heat island driving temperatures hotter for 150 years.
I see Richmond RAAF 67105 had Jan 2017 mean max = 34.1, mean min = 20.
I only have to check historic monthly mean max and min for Richmond – UWS Hawkesbury 67021 to find that 1946 equalled the Jan 2017 max of 34.1 and smashed the min by a whole degree. So obviously all the BoM claims for last month are rendered so pathetically tenous and lineball (without plugging in a “correction for UHI”) – what a disgusting propagandist organization the BoM has become.

BoM exaggerates again Canberra hottest January

Claiming Canberra had its hottest January – Hottest January on record sees Canberra’s power usage soarCanberra Airport 70351 had Jan 2017 mean max 32.8 but Queanbeyan Bowling Club 70072 in 1932 had a Jan mean max of 34.2 –
When you examine site differences, ponder the UHI growth in the ACT – Qbn UHI in 1932 – it looks too close to call. Definitely not a worthy record for the BoM to trumpet.

Sydney record hot night – urban heat island never mentioned

Dear old Bureau of Meteorology up to usual tricks claiming a hottest evah record hot night for Sydney but ignoring the UHI. The record is not worth the paper it is printed on due to the huge urban heat island UHI.
Sydney weather: Overnight temperature is record high for December, BOM says
AWN lets you look around the region and see that the night of the 14th was warmest in the Sydney core stations, Obs Hill 27.1, Airport 27.5, Parramatta 27.5. Note RICHMOND RAAF (067105) at 23.6 further west in the UHI – the record there for Dec is 25 in 2000. The earlier RICHMOND RAAF (067033) 1928-1994 has 25.5 in 1990 as the record Dec night. All pointing to this warm night event being nothing special – unless you want to beat up global warming.

Perth heading for coldest September since at least 1906

Chris Gillham in Perth has been monitoring mean daily temperatures at Perth BoM sites and says Perth Airport 9021 is a shoo-in to have the coldest September mean since opening in 1944. Perth Metro 9225 in Mount Lawley has only been open from Jan 1994 replaced Perth Regional Office 9034 which commenced 1897 and underwent various moves before ending up in East Perth. Progress with temperature updates can be checked at AWN or the BoM.
Chris has a page discussing the history of various Perth weather stations since 1897. I will update as the final numbers are available and hope to include other Perth region sites such as Pearce – Jandakot – Medina etc It is amazing we can have a month like this in the teeth of the vast Perth urban heat island.

Sydney hottest April day last Wednesday only happened at Observatory Hill

The centre of our largest urban heat island reached 34.2 on 6 Apr 2016 topping 33.9 from 5 Apr 1986.
Other stations I have checked that were open in 1986 were all hotter in April 1986.
Sydney Airport 34.7 on 6 Apr 2016 but 35.7 on 4 Apr 1986
Bankstown AP 35.8 on 6 Apr 2016 but 36.9 on 4 Apr 1986
Parramatta Nth 35.2 on 6 Apr 2016 but 37 on 4 Apr 1986
Richmond RAAF(067105) 36.6 on 6 Apr 2016 but Richmond RAAF(067033) 38.2 on 4 Apr 1986
The ABC TV weather news was beating up Penrith but that station did not open until 1995 and there seems to be no other Penrith station – tough – what liars.

Looking at the state I have checked Goulburn, Condobolin, Cobar, Bourke – the first 3 were all hotter in Apr 1986. Bourke Post Office was hotter 3 times between 1906 and 1922. So just now I can not find that 6 April made a record hot day anywhere in NSW except Sydney Obs Hill – any suggestions? This would be remarkable.

Perth 4 days over 40°C heatwave nothing out of the ordinary for Perth heatwaves

We have all seen the media beat ups about the “Great Four day Perth heatwave 7th to 10th Feb 2016” – never a mention that that the ever expanding Perth urban heat island UHI might contribute to this event. Credit where credit is due though, the original BoM forecast was pretty good. Unlike their Brisbane and Queensland efforts this year.
Check out the statistics assembled by Chris Gillham in Perth – his website has much information on WA and Perth climate matters. Interesting that Perth Airport temperature data shows the “Great Four day Perth heatwave 7th to 10th Feb 2016” was exceeded by several past events at that site.