Record hot day in Sydney 18 Jan 2013 pretty much confined to urban heat island

The Sydney all time hot day record of 45.8 tops the 45.3 on 14 Jan 1939 but is in the centre of our largest urban heat island, so the number has to be seen in that perspective. We are fortunate to have a map of NSW from the Sydney Morning Herald preserved online with max temperatures recorded as at 11 Jan 1939.

A check on how widespread were all-time high temperatures around the Sydney region on the 18 Jan 2013 finds little support for the 18 Jan 2013 being a regional non-urban all-time record hot day. This Table summarises the regional comparisons. Comments follow the Table in the same order.

Sydney Airport was open from 1929 but daily data is only digitised from April 1939.
Richmond RAAF data – no record there – the all-time hot day is 47.8 on 14 Jan 1939 – max on the 18th was 46.4, a long way shy of 47.8.
Newcastle Nobbys Signal Station recorded 42 which equaled the all-time high on 23 Dec 1990. But Nobbys daily data is only available from 1957 – about 90 years of daily data is waiting in archives for this wealthy nation to enter to disk.
Jerrys Plains Post Office is an interesting case – a site little changed over a century, site open 1907-2012 yet daily data has only been digitised from 1957. But we luckily have a map from the Sydney Morning Herald for 14 Jan 1939 showing the heatwave across NSW on the 11th. This shows Jerrys Plain recorded 120°F or 48.9°C. That puts the temperatures quoted in the map on the Australian today in perspective. Nothing like the heat of Jan 1939.
The Scone Airport reading was topped earlier this months by 44.2 on 12 Jan 2013 – so obviously no all-time hot day in Scone. But we note the 11 Jan 1939 SMH map had 114F or 45.5 for Scone which would have been at Scone Philip Street 61069.
Bathurst Ag Station 63005 had a 39 yesterday but has an all-time max of 40.1 15 Feb 2004. No daily data digitised pre 1966.
Picton on the 1939 SMH map recorded 116F – 46.6 and the closest I can find to Picton today is Camden which hit 46.4 on Friday 18 Jan. So so hint of all-time hottest day there.
Cowra on the 1939 SMH map recorded 114F – 45.5, likely at the Cowra Post Office 63021. Cowra Airport on Friday recorded 44.8 but pre 1957 data is not digitised. But no hint of all-time hottest day there.
Canberra on the 1939 SMH map recorded 109F – 42.8, now the Airport 70014 did not commence readings until March 1939 so we do not know for sure where the 109F was measured. In Jan 1939 weather records were kept at Duntroon 70103, Canberra Forest 70015, Canberra Solar Observatory 70100 and Acton 70099. I would guess Acton is the source of the 109F on the SMH map. Canberra Airport on Friday recorded 42 but there was a 42.2 on 1 Feb 1968 so no hint of all-time hottest day in the National Capital.
The SMH map shows Jervis Bay near Nowra was not notably hot on 11 Jan 1939 and I can not locate pre 1955 data to check against the 45.4 on last Friday.
Bega has no pre 1965 daily data available so the 44.6 on last Friday is hard to assess.
Moruya was entered on the SMH map at 111F – 43.9 no doubt from the long term station Moruya Heads Pilot Station which only has dailies entered from 1957. On Friday last Moruya recorded 43.8, so once again the all-time hottest day record still stands.
Summing up it looks obvious that claims of Sydneys hottest day ever on 18 Jan 2013 are not supported by surrounding regional stations. Everything the Australian BoM promotes in our main stream media needs examining with a fine-tooth comb.

8 thoughts on “Record hot day in Sydney 18 Jan 2013 pretty much confined to urban heat island”

  1. As you say, just lucky we have a newspaper map for 11 January 1939 to give a straight comparison with the 18 January 2013 scorcher. Amazing that after 25 years of greenhouse panicking with all the associated fuss over warming and extreme temperatures, the BoM still hasn’t bothered to digitise our country’s temperature data.

    On the evidence of the map, Sydney Observatory Hill has a new record on 18 January 2013 but for the vast majority of places in the state, 11 January 1939 was hotter. Newcastle and Sydney Airport are only possible new records, assuming the shading on the old map is reliable – the BoM has not archived the figures for 1939 so we cannot be sure. Both places would be subject to increased urban heat island effects now compared to then, as is Observatory Hill. In every other case where we can check – Scone, Richmond, Cowra, Canberra, Moruya – 1939 was hotter.

    Surely with all the billions generated by the carbon tax the BoM could afford to pay some students $15 or $20 an hour to make a permanent record of Australia’s temperature data so we can see for sure whether records are being broken or not? Or don’t they really want to know?

    By the way the caption underneath the map at the original source (the Sydney Morning Herald) suggests that other days in January 1939 might hold the record for some of the stations. It reads:

    “This map, based on the officially recorded maximum temperatures throughout New South Wales on Wednesday, can be taken as typical of any day during the past fortnight. The heavily shaded portion shows the large proportion of the State that experienced temperatures exceeding 110 degrees. The registration of 124 degrees at White Cliffs was the highest recorded in New South Wales since the record for the state, 125 degrees, was made at Bourke in 1909.”

  2. Before Warwick put up this post I made this comment at Tallbloke’ s blog

    cementafriend says:
    January 20, 2013 at 12:49 am

    Interesting that there was a spike of CO2 in the northern hemisphere in 1940. see here or the partial translation of Kreutz’s paper on my higher temperature and solar radiation arriving at the surface leading to outgassing of CO2 from the ocean followed by shifts in the jetstream. Looking at some random weather stations in Australia it seems that the summer of 1939 was very hot (eg a max of 47.8C/118F at Cobar NSW in Jan) but that the summer of 1941 was relatively cool (eg Cobar max temps in Jan around 30C and none over 40C)

  3. Moruya. Two stations:

    Old pilot station (data available for c. 50 years) Max on 18 Jan 2013 – 43.8

    Moruya airport AWS (data available for c. 10 yrs) Max on 18 Jan 2013 – 45.9

    Wonder why they used the airport?

  4. A well known ABC publicist once told me that the greatest adage of any alarmist is “talk it up while its hot and lay low while it is cool.”

    The froth with which the ABC (and Fairfax) have covered, not only the events, but with additional commentary about human impact has turned me off the entire circus. Watching 7.30 on ABC last week, the stand-in interviewer who was obviously trying to make a name for himself asked a BOM bureaucrat over and over again; “what impact have humans had?”

    Last year, Alex Sloan on ABC radio scorned Senator Joyce for not believing the carbon tax would decrease world temperatures!!!

  5. this article is worth a read
    a bit of cut and paste

    But no longer. The 2013 prize for Sensationalist Scaremongering without a Skerrick of Proof goes to the intellectuals’ TV station of choice — our very own ABC. Over the past week, our national broadcaster has sunk to previously unimaginable depths of vacuous, inane and wholly misleading reporting on the issue of climate change. Tossing aside any pretence of being an objective commentator on the subject, this taxpayer-funded behemoth has become the simpering, toadying transmitter of government propaganda.

    Timing its ‘special reports’ to coincide with the bushfires, er, sorry, I mean the IPCC conference in Hobart, ABC News has become a captive of left-wing hysteria, government spin and UN bureau-waffle.

    Replayed with alarming (in both senses of the word) regularity, viewers have been treated — during the national news, no less — to a trailer for what purports to be an investigative series, yet turns out to be rehashed claims (yes, we know the IPCC is ‘nearly’ certain that climate change is ‘human-induced’) graphically dramatised with endless Gore-esque clips of eroded beaches, bushfires, ice floes and so on. Stock-shot libraries must get on their knees each morning and thank the Lord for our variable climate. How else would they ever flog those hours of useless footage of waves crashing against crumbling beaches?

    The ABC News website currently resembles a Department of Climate Change schools brochure, with childish graphs showing ‘how the carbon tax works’. On air, news pieces effortlessly slide from bushfire horror stories to extreme climate change hypotheses, hysterical predictions and unsubstantiated claims courtesy of the ‘closed doors’ Hobart IPCC conflab. Most disgraceful of all is the shot in the trailer of a serious-looking, grey-haired gentleman who warns us that homebuyers are fleeing in droves from soon-to-be deluged and massively devalued coastal homes.


    Does it bother anyone else that Juanita Phillips, the popular news anchor who is spending the week neatly conflating the national news with what is little more than government spin, is apparently in a relationship with the Climate Change minister, Greg Combet? I thought that sort of cosy partnership only existed in France. In the UK, Rebekah Brooks was flayed alive for her proximity to PM David Cameron.

  6. Cementafriend

    I ran the raw temps for Bourke and Cobar for the 10th Jan, 1939 and compared them to the new ACORN temp record. Just about every daily temp was changed and some by quite a bit.
    For instance, a 40C was reduced to 39.1 for Bourke (2nd Jan) and the hottest day of 48.3C was reduced to 47.9C. This reduced Bourke’s max mean temp by nearly 0.4C over the month.
    Surprisingly, Cobar had its temps marginally increased. The end result was that Bourke had the highest monthly max mean using raw temps but Cobar had the highest max mean using ACORN’s temps. Go figure.

  7. Warwick,
    How was temperature being measured and recorded at OH in 1939, compared with today ?
    What was the accuracy of the measurements ?
    It is curious that on Friday, temperatures were 16 degrees lower on Sydney Harbour, just 5 km East and an Easterly was recorded at OH at the time of the max.

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