But the BoM fails to say that outside the Hobart urban heat island (UHI) record warmth is harder to find.
I checked the following stations around the Hobart region – first the mean monthly max – only Tasman Island agreed with Hobart but the site has only operated from 2002.
then the mean monthly min gives a similar result.
So the BoM should have told the ABC that although central Hobart had a record warm October – few other sites in the district confirmed that so on balance you would assume that the UHI effect has been quietly ramping up warmth in Hobart data for a ~century.
Warming trends showing up strongest in the cooler months. Data is from a Govt fruit research institute the Marlborough Research Centre on the town outskirts. Charts by the MRC. Blenheim population growth. Small town temperature data – often classed as “rural” in global databases – can usually be shown to be riddled with UHI warming.
Click for monthly charts – January — February —March —April—May—June—July—August—September—October—November—December
Here are the monthly trends in degrees C as per MRC.
Trends 1932 to 2011 or 2012.
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.
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
That is since 1939 against ever growing UHI – 1st to the 6th all frosts – data from CDO. 73rd Anniversay of the D Day Normandy landings in 1944.
Another of these cases where rain could have been enhanced by urban areas.
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.
Claiming Canberra had its hottest January – Hottest January on record sees Canberra’s power usage soar – Canberra 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.
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.
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.