The Australian Temperature Record – Part 7: New South Wales

Ken Stewart, July 2010

 The last State to look at is Australia’s first State, New South Wales.  NSW is the oldest, most populous, and richest in the Commonwealth.   Although their State of Origin record is pretty dismal of late, they outclass Queensland in one field- adjustments to their temperature record.

The Australian Bureau of Meteorology (BOM) develops its climate Trend Maps and Time Series graphs form 100 sites nationwide, comprising the High Quality Australian Site Network.  17 of these are in New South Wales. 

Here is a map of the sites:

Here’s the Trend Map:

And Time Series Graph:

As you can see, BOM declares a warming trend of 0.08C per decade, or 0.8 degrees C for the last 100 years.

I have now completed (almost) the first independent study of the High Quality Australian Site Network, and as part of that project have analysed the data from the New South Wales sites.  I averaged maxima and minima for all stations at each site, then compared with the High Quality means.  Please note: at this stage I have only looked at the non-urban sites, as BOM says the Urban sites are excluded.  BOM has adjusted the raw data to clean up errors and discontinuities, by a method described in Part 1: Queensland.  A spokesperson for BOM has asserted that: 

“On the issue of adjustments you find that these have a near zero impact on the all Australian temperature because these tend to be equally positive and negative across the network (as would be expected given they are adjustments for random station changes).”

Compare this with the results:

Based on an average of trends at these sites, there is a 36% warming bias!

Here’s a Graph of the size of adjustments:

Once again you will notice that there are 4 stations whose trends have been reduced, 3 which are essentially unchanged, and 10 warmed. 

You will also notice that the State trend (0.8) is obviously not the same as the above calculation.  It must be derived by averaging all the data and then finding the linear trend.  Here is a graph of the raw and HQ record for all 17 non-urban stations and the resulting trend:

This shows the raw trend at 0.5 degrees C per 100 years, and the High Quality trend at 0.75 degrees.  BOM rounds this to 0.8.  That’s a warming bias of 60%!

This study is only looking at the 100 stations that BOM uses for the official climate record, that is, the non- urban sites.   BOM does not use urban sites, and until now I have assumed this is because they want the High Quality record to be free from contamination by such things as Urban Heat Island effect.  Never assume.  It is easy to compare the average trend of NSW as a whole (0.8 C) with that of the Urban sites.  The average of the Urban stations is less than 0.6 degrees C per 100 years!  In other words, they are warming less rapidly than the non- urban sites.  Interesting-  I wonder why?   That will be the subject of another study.

But there is another peculiarity about NSW.  Many of the High Quality data records have the final few years missing.  Have a look at this plot of the number of stations with raw and adjusted data available in each year:

The mid- century loss of raw data is plainly obvious- this occurs throughout Australia.  But you also see that BOM has not continued the High Quality data to 2009 in many cases- indeed in 2007 a third of the HQ record is missing!

Let’s look at the individual stations.

Tibooburra is in the remote north west.  Raw data:


BOM slightly cools this record.  Note BOM also corrects the 1931 plunge.

Wilcannia, also in the northwest.  Note the years of missing data, infilled from “nearby” White Cliffs.

Adjusted, from 0.45 to 0.6 C/100 years.

Cobar  raw, a combination of 4 stations:

The HQ splice:

Adjusted, reduced from 0.7 to 0.6:

Bourke, also in the north west, shows  2 records that don’t overlap.  The older record shows a cooling of -0.2C /100 years:

But the HQ data has been simply combined and adjusted to show a warming of 0.7C!  The raw data spliced in this way shows only 0.3C/ 100 years.  I have gone with this even though I disagree, to compare the two.

Walgett similarly has 2 non-overlapping records:

But this time BOM has decreased the earlier data to match.  As they didn’t do this at Bourke, to be consistent I have kept the raw data.  What’s good for the goose as they say.  Warming increased from 0.5 to 0.9C.

Tenterfield is near the Queensland border in high and cold country.  It is the town where Sir Henry Parkes made a famous speech in favour of Federation, and the home of entertainer Peter Allen.  The raw data has gaps, but is comparable with Wallangarra only 16km away on the border, and is flat- about 0.15C warming.

The HQ data has been adjusted and has 0.4C warming.

Glen Innes, further south and also high and cold, and appears to have a noticeable UHI effect:


This is a rare example of a record being adjusted to correct UHI: from 1.15 to 0.5.  Well done, BOM.  But why the difference in temperatures?

Yamba Pilot Station on the far north coast has 0.65C warming, mostly since 1980:

This has been adjusted to 1.2C/ 100 years!

Jerry’s Plains, inland from Newcastle, has a clear cooling then warming trend, and overall is almost flat:

Adjusted, from 0.05 to 0.5!

Mudgee’s older record shows an almost flat trend of 0.1:

On the basis of 4 years overlap BOM has reduced the earlier data to match the Airport , but keeps the trend at 0.15.

Cowra, scene of a World War II POW camp which saw a mass breakout by Japanese prisoners, has 4 records:

I made a splice by combining the older record with the overlapping Resource Centre, whereas BOM used the Comparison site and reduced the older data:

0.6 to 1.3C /100 years:

Richmond RAAF base is listed by Torok (1996) as an Urban site, not to be used, and has 3 main records:

Here’s the BOM HQ with raw data to see what they did:

I spliced by reducing the data to 1952 by 0.8, then from 1956 to 1993 by 0.24.  Here’s the result, and HQ’s warmed trend:

Point Perpendicular Lighthouse, south of Sydney, has a raw warming trend of 0.6C, and was replaced with an automatic weather station in 2002. 

BOM doesn’t use this but reduces the warming to 0.15.

Moruya Heads Pilot Station (Jervis Bay) appears to have 2 clear discontinuities:

BOM adjusts only 1955 to 1964, and keeps the rest, so the trend is unchanged.  Odd:

Wagga Wagga has 3 records, Kooringal, Research Centre, and the Aeronautical Met Office, with good overlaps:

I spliced Kooringal less 0.75 (the average difference) with the AMO to get a slope of 0.4C. BOM distrusts the AMO data from 1942 to 1969 and continues the slope backwards to 1910, to produce a warming of 1.3C / 100 years:

Deniliquin, in the south west, has a -0.3C cooling trend:

BOM in its wisdom (probably on the basis of the short Falkiner Memorial data 19km away) has adjusted this to give 0.65C warming, and doesn’t even use the airport data:

Perhaps nearby sites also showed this warming?  Not the closest long-term site, Echuca, 72.5km away on the Murray River- identical:

Hay, also in the south west:

Slightly cooled, from 0.9 to 0.8C / 100 years.


When all non-urban stations in the state are averaged, the raw trend is 0.5C/ 100 years, the High Quality trend is 0.75C, which gives a bias of 50%.  BOM rounds the 0.75 to 0.8, which makes it even worse- 60%.

Strangely, the average of the HQ Time Series Graphs for the Urban sites show less than 0.6 C warming per 100 years .

Four stations are cooled, three are left almost as is, and the other 10 have been warmed.

The High Quality record leaves out many stations in the last decade- 2007 has one third missing.

“High Quality” is not an apt description for this record.

I have now completed this check of the High Quality sites which are used to produce the official Australian temperature record.  There appears to be a nation-wide warming bias of 33%.  “Near zero impact”?  This will be the subject of the final post in this series, in about a week.

Many thanks to “janama” for his earlier work and encouragement, and Lance for assisting with downloads.

9 Responses to “The Australian Temperature Record – Part 7: New South Wales”

  1. Ronald Van Wegen Says:

    Your work is/will be invaluable. Data is king. Over time, truth will win out. Thank you.

  2. MarcH Says:

    Looking forward to your summation.

  3. janama Says:

    Although they claim to use only rural data for the national estimate they actually don’t in fact.

    Bourke Airport only has BoM data from 1999 – the rest has been created by adding Brewarrina Hospital data which is clearly urban.

    Same with Glenn Innes airport which also has only 10 years of data, the rest coming from Glenn Innes PO, urban.

    Tenterfield Federation park is in the centre of Tenterfield also urban yet classed as rural.

    Hay Miller street is on the corner of Miller Street and the Sturt Highway – the main highway from the eastern states to SA!

    Yamba Pilot station is on the point at Yamba which has gone from a small coastal holiday village to one of the fastest growing coastal towns in the region and subject to UHI. Heck – they are now arguing about having a Maccas!

    Jerry’s plain is a classic – it’s a small rural town that has stayed pretty much the same without expansion and it shows a flat temperature in it’s raw state yet has been adjusted from .05 to .5 for no apparent reason.

    Lismore Centre Street has rightly been classified as Urban yet 21km away is Casino Airport that has a record back to 1908 but it is not used – possibly because it has a flat trend over the 100 years in the raw form but a .9C rise once it was homogenised by Torok. It’s still operational.

    Congratulations on all your work Ken – great stuff.

    • kenskingdom Says:

      Thanks janama- you know the drill- if it cools, warm it or leave it out; if it warms, keep it or warm it more. Thanks for the local knowledge. I’ll be having a look at all urban sites when I get a chance. Lismore is a beauty. Glen Innes appears to have been corrected for UHI. And Deniliqin- wow! Australain summation is about 1 week away.

  4. Charlie Says:

    This is awesome! See, I don’t really care if there is or isn’t warming, I just hate being lied to.

    It’s pretty clear that the BOM (as well as other government met offices around the world) thought nobody would actually check this stuff out and that they would get away with the – well – lies really, whichever way you spin it.

    I’d love to hear the official explanation for the discrepancy you have uncovered..

  5. Tim Curtin Says:

    Ken et al: Brilliant. But it needs to be published – and BoM needs to be challenged to defend its “adjustments”.

  6. Tim Curtin Says:

    Ken: in any other field eg finance what you have uncovered would be actionable. Do you know anybody at Slater & Gordon?!

  7. Sandy McClintock Says:

    Excellent work Ken. It’s tedious, so thank you for such a ‘magnum opus’.
    Has anyone gone through the ‘homogenisation’ code looking for exactly what they are doing.
    If anyone can extract this code from BOM (and its in FORTRAN) I will happily have a go at checking it out. C++ is not my scene.
    The use of airports seems very strange to me. They start with grass strips and single engined planes but evolve into places that burn tons of fuel and have vast areas of asphalt.

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