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The Official Iceland Temperature Series

February 20, 2015

By Paul Homewood 


With special thanks to Trausti Jonsson,  Senior Meteorologist with the Iceland Met Office.




Now that GHCN and GISS have managed to emasculate the Icelandic temperature record, it is time to present the official version.


The Iceland Met Office, (IMO), have kept meticulous temperature records since the 19thC, including station metadata as well as just the temperature data. In fact the Icelanders took their climate very seriously in those early days, unsurprisingly since they are so vulnerable to climate shifts. There is an interesting overview of the work of people such as Thoroddsen and Nansen in the early 20thC here.


In particular, they have full records since 1931 for seven stations.

It needs to be emphasised that these are not raw temperatures, but have been carefully homogenised and adjusted where necessary, to account for station moves and equipment changes.

Trausti, who has done much of the work himself over the last three decades, explains:



I would again like to make the point that there are two distinct types of adjustments:

1. An absolutely necessary recalculation of the mean because of changes in the observing hours or new information regarding the diurnal cycle of the tempearture. For Reykjavík this mainly applies to the period before 1924.

2. Adjustments for relocations. In this case these are mainly based on comparative measurements made before the last relocation in 1973 and supported by comparisons with stations in the vicinity. Most of these are really cosmetic (only 0.1 or 0.2 deg C). There is a rather large adjustment during the 1931 to 1945 period (- 0.4 deg C, see my blog on the matter – you should read it again:
I am not very comfortable with this large adjustment – it is supposed to be constant throughout the year, but it should probably be seasonally dependent. The location of the station was very bad (on a balcony/rooftop).

I must emphazise that an adjustment on the top of an adjustment is a very bad idea. [GISS – please note!]

One must be very open about the data – and the adjustments used.
It is also important to realise that the adjustment/homogenizing process is always a compromise – information is always lost during the process.

This, of course, is exactly how the procedure should operate.

The homogenised data is available at the IMO website here.


We can take a look a three of the sites, regarded by the IMO as long running and representative.






Across all three sites, we find temperatures in the 1930’s and 40’s up around where they have been during the current warm period. The main difference, however, is how persistent this recent warm weather has been, compared to the 1940’s, where there were some extreme year-on year changes. As Trausti comments “there has not been a single cold year since 1995.”


I have prepared an Iceland Temperature Series, combining these three stations together with other four long running sites of Grimsstadir, Storhofoi, Teigarhorn and Haell, which confirms the picture shown above.

Theses seven sites offer a fairly representative geographic mix, from north to south, and east to west. The chart below is based on anomalies from the 1981-2010 baseline, averaged across the seven sites.





None of the above bears any resemblance to the current GISS record:






The fact that all seven stations show the same pattern as each other is powerful evidence that the GHCN adjustments are grossly in error. 




Iceland Met Office

  1. A C Osborn permalink
    February 20, 2015 7:12 pm

    Paul, “we” are all in agreement on this, it is the defenders of the faith that can’t see that there is anything wrong with what GISS are doing.
    I don’t think it matters what Data you show them, you will never shake their faith.

    • Allan M permalink
      February 21, 2015 10:25 am

      As Upton Sinclair put it: you cannot expect a man to understand something when his salary depends on him not understanding it.

  2. Scott M permalink
    February 20, 2015 7:14 pm

    Its obvious to any well funded Climate scientist, the actuals must be wrong as they dont support the Global Warming models.

  3. Retired Dave permalink
    February 20, 2015 8:17 pm

    Paul, as you have come to understand the Icelandic Met Service is second to none in their treatment of instrumentation, its exposure, changes – and handling of the data. One can understand their disquiet about the robotic changes made by GISS.

    Any meteorologist can relate to Trausti’s discomfort with large adjustments to data but, as he is, be just as uncomfortable with a poor exposure such as he describes.

    It is obvious that Trausti and his colleagues have made any adjustments knowing what they were doing and why they were doing it – I don’t see how GISS could make any such claim.

  4. manicbeancounter permalink
    February 20, 2015 9:23 pm

    The data does show that the last 15 years have been the warmest period on record – even if the record only dates back to 1931 in many cases. Further, the warming since about 1980 is about twice that of the global average, as would be expected in a country on the edge of the Arctic.
    But then the data departs from the official narrative. There was a drop in temperatures of around 1C in the mid-1960s. This was similar in magnitude, but about three years before, the drop in average temperatures across the nine weather stations in Paraguay. Such a drop is completely against the human-caused warming hypothesis, and suggests that the rebound was at least partly not human caused.

  5. Kon Dealer permalink
    February 20, 2015 9:27 pm

    If it looks like a duck, quacks like a duck and walks like a duck, it is a duck.
    By the same token the “psientists” who run GHCN and GISS are fraudsters.

  6. February 20, 2015 10:17 pm

    Is there a way to match the style of the IOM bar charts to the GISS graphs?

  7. Paul2 permalink
    February 20, 2015 11:05 pm

    Have a listen to the latest propaganda from the state warmist broadcaster who are convinced that Iceland is going through something extraordinary:

  8. February 20, 2015 11:15 pm

    Reblogged this on Tallbloke's Talkshop.

  9. AndyG55 permalink
    February 21, 2015 12:23 am

    Thought you might like this

  10. February 21, 2015 1:53 am

    Reblogged this on the WeatherAction News Blog.

  11. February 21, 2015 4:50 am

    Taking a step back from algorithm problems, this is really a top-level product design problem, obviously the Icelanders (and others) should provide their climate history as an INPUT to what GISS produce.

    C’mon NASA, its not rocket science.

  12. Doug Proctor permalink
    February 21, 2015 5:46 am

    You need to show the GISS combined from 1930 to present, or better yet, the difference between the Icelandic and GISS station reconstructions, and a combined difference. The GISS position is that errors are random and average out.

    Apples to apples and crucify the excuse.

  13. JWood-the-other permalink
    February 21, 2015 5:58 am

    It has become a religion to these people. It’s impossible to shake the true believer out of their faith. When their high priests decree what to believe, they will defend it to the grave.

  14. February 21, 2015 6:06 am

    “Now that GHCN and GISS have managed to emasculate the Icelandic temperature record, it is time to present the official version.”

    This is complete nonsense. GHCN has not emasculated the record. You just wilfully look in the wrong place. GHCN unadjusted is here. tavg.latest.qcu. And it is exactly the same, with occasional rounding differences, as your “official” version. A table for Reykjavik is here. The only difference is that GHCN goes a lot further back.

    I think it is reprehensible that Trausti Jonsson plays along with this misinforming.

    • AndyG55 permalink
      February 21, 2015 8:37 am

      Now show us the CURRENT, 2015 Reykjavik GISS series.

      There is absolutely no date attached to the data you link to.

      CURRENT GISS, please, direct link.

    • AndyG55 permalink
      February 21, 2015 8:44 am

      Oh look , Here it is

      The data in your second link CLEARLY shows 1938ish higher than now.

      Yet the current GISS has been massively TAMPERED with.

      What the **** is wrong with you, did you think no-one would check !? Fool !

      I used to think you might have had something to offer,

      … now I see you are nothing but a LYING propagandist !!

      • February 21, 2015 8:54 am

        “Oh look , Here it is”,/i>
        I said nothing about GISS. I said Paul’s “official” series was exactly the same as GHCN unadjusted. There is plenty of data at that link. You just can’t deal with it.

        GISS is mostly the same as GHCN adjusted. Get it? A-d-j-u-s-t-e-d. It’s different.

      • February 21, 2015 11:55 am

        Where have you been for the last month, Nick?

        It is the “adjustments” that we have complaining about.

      • AndyG55 permalink
        February 21, 2015 9:01 am

        “A-d-j-u-s-t-e-d. It’s different.”

        Yes, GISS is a fabrication, Nothing like the real data.

        Stop trying to defend the indefensible.

        It makes you look very stupid.

    • AndyG55 permalink
      February 21, 2015 8:54 am

      The top 6 GHCN values from your second data link are..

      1939 6.3
      1941 6.3
      1945 6.1
      2003 6.1
      2014 6
      2010 5.9

      Now compare that with the link to the GISS fabrication.

      Its disgusting that you could even pretend that there is no falsification !!

    • February 21, 2015 11:52 am

      What, the “unadjusted” version before it get “adjusted”?

    • February 21, 2015 12:07 pm

      BTW Nick

      The GHCN unadjusted are not exactly the same as the IMO figures. As Trausti points out, the latter have been carefully adjusted where necessary, e.g. Reykjavik between 1931 and 1945, when the station moved. During this period, the IMO figures are 0.4C lower than GISS show for GHCN V2 raw.

      • February 21, 2015 2:46 pm

        “As Trausti points out, the latter have been carefully adjusted where necessary, e.g. Reykjavik between 1931 and 1945, when the station moved.”

        Well, we can’t tell. If you go to his “official figures”, those years are missing entirely.

        The numbers on that file are the same as for GHCN unadjusted. TJ may have added his own wisdom (“fabrication”?), but it made no difference.

      • February 21, 2015 4:24 pm


        It’s not very clear, but the IMO website holds data back to 1931 (see Longer Series).

        These are all official IMO data.

        The original data can be seen here. You can spot the Reykjavik and also Stykkisholmur adj from there.

      • AndyG55 permalink
        February 21, 2015 8:47 pm

        The big point is that the current GHCN/GISS bares no resemblance to any of the slight variations of the original Reykjavik data.

        It has had the 1940’s peak squashed and the whole thing mutilated to CREATE a warming trend.

        Just like sooooo many other places, same pattern of mal-adjustments.

        This is how the world has warmed.

      • February 22, 2015 11:29 am

        As usual Nick Stokes points to squirrels to try to divert attention from the issue being discussed. I too hoped that he had something valid to add to the climate debate but not so now.

  15. Kon Dealer permalink
    February 21, 2015 1:00 pm

    Typical Nick Stokes contribution.
    His doctorate is in misdirection.

  16. February 21, 2015 3:06 pm

    It looks like to me that the correct temperature data for Iceland, correlates strongly to the phase of the AMO/PDO.

    • February 21, 2015 8:21 pm

      It probably should correlate to Atlantic cycles (there is more than just AMO) given its geographic location and size.

  17. February 21, 2015 4:42 pm

    Data file for the Reykjavik annual temperature, I recorded sometime in 2011, shows 1939 and 1941 at 6.4C (see bottom graph, while in the graph above is shown to be around 5.8C

  18. February 21, 2015 7:52 pm

    I see Nick Stokes is again defending the liars. Imagine my surprise.

  19. manicbeancounter permalink
    February 23, 2015 11:10 pm

    I have taken a detailed look at the Reykavik adjustments by both GHCN and GISS. All the issues lie with the GHCN. The raw data shows that
    – The early twentieth century warming was very similar in magnitude to the late twentieth century warming.
    – The peaks in warming were virtually the same.
    The adjustments drastically reduce the size of the early twentieth century warming along with the subsequent cooling. The change in the all-important data story is below.

    I also checked the changes in the adjustments with the frequent changes in station relocation. They do not match up at all. Both GHCN and GISS have ignored the metadata.


  1. A Well Done Comparison of Iceland Temperatures V.S. GIStemp Fantasies | Musings from the Chiefio
  2. Reykjavik Temperature Adjustments – a comparison | ManicBeancounter
  3. Iceland Bradford | Thai-Iceland
  4. The Official Iceland Temperature Series – 2015 – Web-Log9

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