Jump to content
Thunder?
Local
Radar
Pollen
IGNORED

Updated CET data base v2.0 posted (9 May 2022) -- an ongoing analysis of changes made to what they now call the "legacy" data base


Recommended Posts

Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    I just found out by accident that the CET data base upgrade (announced to be imminent last year) has gone forward as of today. 

    This thread will be for discussion of the changes made from the "legacy" data base that we have all been using for aeons, to the "current" or v2.0 data base.

    My first quick impression was that some of the temperatures have been adjusted by about 0.1 or 0.2 C deg. For example, Dec 2015 is now shown with a mean of 9.6 rather than the old 9.7, and the tie between 1934 and 1974 at 8.1 now looks like this -- 1934 8.1 and 1974 7.9. Nov 1994 is down from 10.1 to 9.9. July 2006 is up from 19.7 to 19.8 ... some other monthly extremes are 0.1 higher or lower than before. It does not look as though many changes have been made before some year that I have not worked out yet but it's around 1970 (later edit it was 1974). So the "legacy" values will be the same for most of the older data. 

    Your bookmark may not work for the CET data base, here's the new location. 

    https://www.metoffice.gov.uk/hadobs/hadcet/data/download.html

    More on the comparisons as I go through the new data base and compare it to the legacy data base. 

    Edited by Roger J Smith
    • Like 1
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    So, I have downloaded the new monthly averages and compared to my data file for "legacy" monthly averages. 

    It appears that small changes have been applied to the period 1974 to the present. However, there are very infrequent small changes made to older data too. It amounts to less than twenty months in the interval 1788 to 1973. I don't see any changes to the oldest data which was only precise to within 0.5 in its original form anyway. 

    The changes made to various months 1974 to present are almost all of 0.1 or 0.2, in either direction. The average change made is just about 0.0, and it appears that there are some segments that go up consistently and some that go down consistently. The following is a copy of my table of differentials for 1974 to 2022. I will post the earlier differentials below this in just anecdotal form. 

    TABLE OF MONTHLY DIFFERENTIALS 1974 to 2022 (CURRENT 2.0 minus LEGACY CET)

    A positive value in this table means that the new 2.0 version CET is higher than the legacy version. 

    A negative value means that the new 2.0 version CET is lower than the legacy version. 

    Values of 0.0 appear for months with no changes to mean temperatures. 

    __________________________________


    image.thumb.png.35da85cd75b7dac051c55f10d0531b29.png

     

    Before 1974 the only months to show changes are: 

    (in reverse chronological order)

    1969 _ Oct +0.1 and Dec -0.1

    1968 _ Jan _ +0.1

    1916 _ Jan _ +0.1

    1914 _ June _ +0.1

    1890 _ Feb _ +0.1

    1884 _ Jan _ -0.1

    1869 _ Dec _ -0.1

    1864 _ Oct _ -0.1

    1860 _ Dec _ -0.3

    1856 _ Apr _ -0.2

    1853 _ Oct _ +0.1

    1798 _ Apr _ -0.1

    1797 _ Apr _ -0.1

    1792 _ Nov _ -0.1

    1788 _ June, Nov _ -0.1

    (a reminder, the negatives are now lower by that amount, the positives are now higher by that amount, in v2.0). 

    _ it may be the case that one or two of the above reveal errors in my transcription of older values so I am going to check into that case by case. (edit ... no these are all actual legacy to current changes)

    Will check into daily data changes ... as to annual averages, those have changed in the general sense that they used to employ two decimals and now have a precision of only one decimal. Since I generated my own from the data tables I have no easy way of telling what changes have occurred in annual means. They are not likely to be very significant with the random nature of the month to month changes. 

    The change to Oct 1969 brought it within 0.1 of the monthly extreme still attributed to Oct 2001 which dropped by 0.1 ... and past formerly second warmest Oct 2005 which is now third. 

    I don't think there are any "shockers" in this new data, just a bit of reordering within narrow bounds. 

     

     

    Edited by Roger J Smith
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Dublin, Ireland
  • Weather Preferences: Cold, snowy winters and warm, sunny summers
  • Location: Dublin, Ireland

    Some I noticed whilst looking through. Not going to list every one, just some of the more interesting ones.

    June 1991 11.9C, 0.2 down from 12.1C

    June 2003 15.9C, 0.2 down from 16.1C

    July 2003 17.4C, 0.2 down from 17.6C

    June 2005 15.8C, 0.3 up from 15.5C

    November 2010 5.1C, 0.1 down from 5.2C

    April 2011 11.9C, 0.1 up from 11.8C

    October 2012 9.5C, 0.2 down from 9.7C

    July 2013 18.5C, 0.2 up from 18.3C

    July 2014 17.9C, 0.2 up from 17.7C

    July 2018 19.3C, 0.2 up from 19.1C

    August 2018 16.8C, 0.2 up from 16.6C

    October 2019 9.8C, 0.2 down from 10.0C

    February 2021 5.3C, 0.2 up from 5.1C

    May 2021 10.3C, 0.2 up from 10.1C

    August 2021 16.0C, 0.2 up from 15.8C

    September 2021 16.0C, 0.1 up from 15.9C

    ------------------------------

    Summer 2018 17.4C, 0.1C up from 17.3C. Now warmer than Summer 1995 which has dropped by 0.1C. Essentially swapped figures.

    • Like 1
    • Thanks 3
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    There is no longer missing data for the 31 daily averages of Dec 1786 but what they have now still average 2.8 as shown before. 

    And I just thought of this, the missing 5.9 for Dec CET is ... suspense ... scroll down 

     

     

     

     

     

     

     

     

     

     

     

     

     

    no longer missing, 1977, 2011 and 2016 all shifted to 5.9 from whatever they were before. 

    Going through the new ranked tables to see if we have a new "missing" phenomenon like 5.9 was until this very moment. 

    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    A lot of new details to check out. I think that they may now be ranking months by unshown second decimal values because otherwise the ties are listed in random non-chronological order. For example, the ranking of months for Jan at 4.3 show 1791, 1996, 1824, 1962, 1734 whereas before that would have been 1734, 1791, 1824, 1962, 1996 from top to bottom. 

     

    These are the new missing CET values closest to their monthly medians ... now we don't have one quite like the old 5.9 December but 11.6 for October is not far off, it would rank the same as 6.5 for Dec (around 29th warmest). I think 11.6 had a value in the "legacy" CET means so it's a new opening. Most of these are the same as before ...

     

    ___ UPDATED CET v2.0 MISSING CET VALUES ___

    Month ___ Colder ___ Warmer

    JAN _______ -0.5 ____ 7.2

    FEB ________1.3 ____ 7.4

    MAR _______2.6 ____ 8.4

    APR ________5.6 ___10.4

    MAY _______ --- ____13.2 __  (all lower values present to extreme 8.5)

    JUN _______ 11.7 __16.3

    JUL ________ --- ____ 18.6 __ (all lower values present to extreme 13.4)

    AUG ______13.4 ___17.9

    SEP _______10.9 ___15.5

    OCT _______ 6.8 ___11.6

    NOV _______ 3.8 ___ 8.8

    DEC ________0.9 ___ 7.0

     

    • Like 1
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    A check of the oldest revised monthly mean (June 1788) shows that there are no revisions to daily data there, which may mean that the new mean is simply a rounding phenomenon using the same data and different protocols on rounding. This fits the fact that there are no revised monthly means before daily data began in 1772. 

    I have not checked all of those older months and it seems likely that actual changes in daily values led to the revisions closer to the onset of more regular changes. Rounding alone would not explain why suddenly after 1974 most months were being revised by 0.1 or 0.2 and I expect to find some changes in daily data when I have the chance to compare the two sets. Looking at a few well-known record values, those have not been adjusted. 

    One exception to the above is that December 1860 has entirely new daily averages for every day and changed from 1.5 in the "legacy" data base to 1.2 in the v2.0 data base. There may be other new data that far back, I have not had a chance to run a differential analysis on the two data bases yet. But just looking at well known daily extremes like 19.7 on 29 Apr 1775 those remain the same. 

    Edited by Roger J Smith
    • Like 1
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Have checked daily data 1772-1851 so far, no changes other than the introduction of actual daily data for previously missing Dec 1786. 

    No changes to 1852 but they start to make small changes in 1853 and this continues to 1859 (so far) with the larger changes to come in Dec 1860. These daily changes are on the order of 0.1 to 0.3 C. 

    It just occurred to me that they might be working on their data base and that maybe I should wait a week or two before doing this. If they are working on it and going backwards through the daily data I may have caught up to where they are as of now (1853). So I will keep going since whatever changes they may have already made will be ahead of where I am now.

    Unless I edit this would expect that 1860 to 1973 will show various slight changes here and there, then more frequent changes 1974 to 2022. 

    My data base is arranged in columns of eight years so I am checking differentials one column at a time, will probably take about a day to get past the mostly similar portion then I expect lots of small changes 1974 to present, will just need to create my data base as before and check various products posted in historical weather section to see what changes are needed in those. 

    Have to wonder where they found daily data for Dec 1786. 

     

    Edited by Roger J Smith
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Herne Bay, Kent (14 m)
  • Weather Preferences: Thunderstorms & Snow
  • Location: Herne Bay, Kent (14 m)
    11 hours ago, Roger J Smith said:

     

    Have to wonder where they found daily data for Dec 1786. 

     

    image.thumb.png.a2613b953edd90973d1ab839327c2823.png

    Syon House by the looks

    https://www.metoffice.gov.uk/hadobs/hadcet/HadCET_v2_guidance_notes.pdf

    • Like 2
    • Thanks 1
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Thanks Jamie, that also clears up my question about the work in progress, looks like I can expect the daily values before 1853 to remain fixed and the work is complete. I haven't got as far as 1880s yet where I found an error in the old data, where one daily minimum was higher than the daily maximum. (I found this by accident when I set about determining the smallest daily ranges on record and found one to be negative). Will check that out and see if it was spotted and corrected. Just getting back into my review now having reached end of 1859 last night before calling it a day and a half. Will post what I find out about size of 1860 to 1973 changes next. 

    The changes from 1853 to 1859 (seven years inclusive) work out to an average of only -0.0002 C over 2556 days, of which 1348 were unchanged and 1208 received adjustments. Notably the cold spell in Feb 1855 is largely unchanged and record warm temps in Dec 1856 have been reduced by a tenth or two, will have to check at some point whether any of these minor changes produce any new records or break any former ties in the records. 

    Edited by Roger J Smith
    • Like 1
    • Thanks 1
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    I will edit in further observations in groups of eight years as I move forward. For 1860 to 1867, the changes remain generally small. In those eight years the average daily adjustment is -0.012 C and there are 1538 of 2922 days unchanged, or 1384 with changes. However, for whatever reason, the month of Dec 1860 has been subjected to a larger decrease that averages over 0.3 C and results in the daily mean dropping from 1.5 (legacy) to 1.2 (v2.0). The second half of the month is quite cold but I don't think there were any values close enough to records before to become new records now. This larger adjustment fades out quickly after the end of the month although there is a second interval with a few -0.2 adjustments in a row in Jan 1861. On now to 1868-75 and beyond. Will edit in observations of the adjustments that I find there. 

    For 1868-75 the adjustment averages +0.002 and a similar number of days (1596) are unchanged, with 1326 changes. The first half of Jan 1868 contains an interval where they warm the values by 0.2, but the month remains at 3.9 albeit warming from 3.85 (legacy) to 3.90 (v2.0), so it takes a fairly consistent push in one direction of these changes to produce a change in mean monthly unless the old value was very close to a rounding point and the push is across that boundary (in this case it was away from it). The very warm days in summer 1868 seem to have been left within 0.1 of previous values. 

    Looking at 1876-83, the changes proceed at about the same pace for 1876, 1877, and then we get into the revised daily max and min era (1878 to present) which seems to increase the range of the adjustments considerably although it does not have much effect on the overall average which for the eight years was +0.00055 C. The number of days adjusted increases to 2271 out of 2922. There are individual days that have changed by over 1.0 C and the largest adjustment was +2.5 for 8 Dec 1879 which went from -3.7 to -1.2. Despite that the monthly average came out the same (0.7). The largest downward adjustment was -1.5 C. 

    For 1884-91, the changes become even more frequent but the average of them remains very small, this time -0.0001 C. This comes from an evidently balanced total of 2531/2922 changes to daily means, this time ranging from +1.5 to -2.2 in amplitude. The error that I had noted in the legacy data for 23 Dec 1884 where the minimum is higher than the maximum remains in this new data set. I suppose it might not be an actual error if the time periods allowed for maximum and minimum do not overlap (in which case I would be surprised that there is only one case in the legacy set, unknown at this point how many are in the new set). Just for the record, the legacy values for this questionable pair were max -2.6 and min 0.5 and now they are max -2.4 and min 0.6. I will contact T. Legg about this some time after I finish this project, but if anyone is in regular contact with him perhaps you could flag this apparent error and ask if there's a reasonable explanation for it. No guarantee of course that the v2.0 has not created one or two more of these somehow. As I mentioned earlier, I found this apparent error in the course of trying to work out what was the lowest daily range in the history of the series. Surprised of course to discover a -3.1 value in my matrix of differentials all of which were otherwise 0.0 or greater. By the way if that is an error then the smallest daily range was actually 0.0 on two occasions. (max and min the same value) Those were 15 Dec 1903 (max, min both 3.7) and 16 Jan 1970 (max, min both 6.4). 

    Some of the coldest days of record cold Dec 1890 have been adjusted to warmer values (22nd was -6.8 is now -5.7) but the monthly average itself remains -0.8 and even to second decimal only shifted slightly. That leaves Dec 2010 in second place at -0.7. 

    For 1892 to 1899, the changes remain in a similar range. The overall average is only +0.00065 C and that involves changes to 2438/2922 daily averages. The range of changes is +1.4 to -1.2 C. The notable cold spell of Feb 1895 is only slightly changed day to day, sometimes colder values now appear. The warm spell of late September 1895 looks fairly similar too but the 27th of Sept has gone up from 19.0 to 19.7 C. 

    The pace of change 1900 to 1907 while similar involves a very slight upturn in the average change to an increase of +0.0016 C deg, which involves changes to 2533/2921 days. The range in the interval is from +2.2 to -1.8. There was a scarcity of notable records in this interval to compare. 

    From 1908 to 1915 the situation is similar to the above, the average change was an increase of +0.0014 C from changes on 2455/2922 days. The range was +1.6 to -3.1 for individual days. The notable cold spell in late April 1908 was subject to very small changes (25th went from 0.5 to 0.6) and the record heat in the summer of 1911 saw some changes that may remove one daily record (in July) but could add another ... also, 13 Aug went up from 23.6 to 23.9 C so its record status should be safe enough. 

    Will continue the analysis in a new post later (1916 to 1971). 

    Edited by Roger J Smith
    • Thanks 1
    Link to comment
    Share on other sites

    Posted
  • Location: Islington
  • Weather Preferences: Freezing cold snowy winters & unsettled summers.
  • Location: Islington

    I don't know if it's been mentioned but one month that got a really big downward adjustment was December 2000: it was 5.8*C, but has now been corrected to 5.3*C - a large correction of half a degree. It seems like overall the year of 2000 saw more corrections downwards of some other years that I've seen. 

    • Like 1
    • Thanks 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Going ahead with the analysis, from 1916 to 1931 things were similar to the ranges described earlier until 1931 started, then the number of changes and their magnitude dropped considerably. This continued to be the case in the 1932 to 1939 data. 

    1916-23 dropped by .0004 C and 1924-31 by .0008 C. Changes occurred on 2529/2922 days in the 1916-23 interval, and on 2321 days by 1924-31, the decrease is largely due to 1931 having fewer changes. 

    A more noticeable shift occurs 1932-39 with the overall change being .00007 C, one tenth the size of previous adjustments, and the number of days changed at all (mostly by 0.1 in either direction) being only 1052/2922. 

    The ranges of larger change values stayed roughly similar, even 1932-39 had one large daily change, +2.7 was applied to Feb 17, 1936 which went from +1.3 to +4.0. But it was quite an outlier among a general sea of 0.1 changes around it. 

    This pattern of mostly very small changes continued 1940 to 1947, which on the average was warmed up by .0014 C deg. Changes were made to 1035/2922 days. There were a couple of outliers from the general pattern of very small changes. Feb 3, 1943 was reduced by 4.2 from 8.9 to 4.7 C. The various records (both warm and cold) from 1945 and 1947 seem to have been left alone with very minor changes made. An interval in March to early April 1946 had a more substantial overhaul. The first part was reduced by almost a degree C then towards a mild spell in late March and early April some considerable additions were made to push that interval warmer by around a degree. That was the only such period in an otherwise nearly featureless void of no change or very small changes in the period. 

    For 1948-55 the changes remain very small and infrequent. The overall average adjustment is +0.0014 C deg. Very few days change by more than 0.1, and 1998/2922 do not change at all (meaning 924 do change). Unlike previous intervals, there are no substantial changes even in isolation. One significant change perhaps is that 29 July 1948, now 25.1 and formerly 25.2 and tied in 2019 by 25 July now raised to 25.3, has slipped to third as 12 Aug 2020 goes up 0.1 to 25.2. 

    Moving on to 1956-63 changes continue to be very small. The period average change is +.0012 C but only 687 days out of 2922 have any adjustments. Notable record periods in 1956, 1957 and 1963 are left alone with no changes greater than 0.1 around record values. 

    From 1964 to 1971 the trends stay similar to the above, mostly very small changes, which average out to +0.0008 C for the interval. Only 769/2922 days received any adjustments and almost all of them were 0.1 up or down. 

    This trend of very small changes continues through 1972 and 1973. 

    There are more substantial and organized changes to the data starting in 1974. My next data post will be about those. 

    Edited by Roger J Smith
    • Thanks 1
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    51 minutes ago, Weather-history said:

    Winter 2015-16 is the mildest winter on that list ahead of 1868-89

    What do you make of the change from two decimals to one decimal in the presentation? They are obviously still using two decimals to rank tied values (otherwise they would be in the chronological order that was used in the legacy tables for monthly values). I don't like that change, the two decimals seemed appropriate to seasonal and annual means. I am also adrift in this brave new world with 5.9 Decembers in it. 

    • Like 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Starting with 1974, many of the monthly averages begin to change by 0.1 or 0.2, and this is because there are organized blocks of changes on that scale in the daily data. Here's an overview of the kinds of changes seen (will keep editing this to completion) ...

    1974 to 1979 _ This interval was generally subjected to a downward adjustment that averaged -.08 to -.10 C per year. Various months are adjusted by similar amounts on most days, conforming to the adjustments in monthly values already posted in the thread (table of adjustments 1974-present). The 1976 heat waves were generally reduced by amounts of 0.1 C per day which will not greatly impact on their place in the records and the hot days in 1975 are left unchanged or in one case 0.1 higher now. Dec 1974 is no longer tied with Dec 1934, it has been dropped by 0.2 to a new average of 7.9 C. Mild weather in autumn 1978 has been subjected to a similar drop. Cold days in winter 1978-79 are less altered, many not changed at all. 

    1980 to 1987 _ The slight negative change fades to -.05 C by 1987. The application of changes follows a similar pattern of blocks of 0.1 to 0.3 adjustments, it gives us slightly colder record lows in Dec 1981 and higher in Jan 1982, takes 0.1 from the heat of July 1983 and the record 20.1 (now) 1st Oct 1985, adds 0.1 to much of Feb 1986 and leaves alone the record cold days of Jan 1987. 

    Will add some observations for 1988 to present later. 

    Edited by Roger J Smith
    • Like 1
    Link to comment
    Share on other sites

    Posted
  • Location: Irlam
  • Location: Irlam
    6 hours ago, Roger J Smith said:

    What do you make of the change from two decimals to one decimal in the presentation? They are obviously still using two decimals to rank tied values (otherwise they would be in the chronological order that was used in the legacy tables for monthly values). I don't like that change, the two decimals seemed appropriate to seasonal and annual means. I am also adrift in this brave new world with 5.9 Decembers in it. 

    Not keen.

    Also some of the figures have been committed to memory but now they have changed. 

    • Like 1
    • Thanks 1
    Link to comment
    Share on other sites

    Posted
  • Location: Edinburgh (previously Chelmsford and Birmingham)
  • Weather Preferences: Unseasonably cold weather (at all times of year), wind, and thunderstorms.
  • Location: Edinburgh (previously Chelmsford and Birmingham)
    42 minutes ago, Weather-history said:

    Not keen.

    Also some of the figures have been committed to memory but now they have changed. 

    Yes, this is particularly annoying 

    • Like 2
    Link to comment
    Share on other sites

    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Yes there are probably quite a few of us with a portion of the brain reserved for CET stats and half of them are now modified at least slightly. I have that entire thread of CET records that will be needing considerable editing although fortunately all the data from 1659 to 1852 remain the same (other than the new daily data for Dec 1786).

    Just added some comments about the 1948 hot spell, 29th July has dropped out of a tie for hottest day (with 25-07-2019) and has also fallen below 12 Aug 2020 into third place. That plus the 1869-2016 switcheroo will no doubt give fuel to any small fires of "data massaging to support climate change" as they remove two talking points about older extremes of warmth. Nothing much they could do to obscure May 1833 or June 1846 however. 

    Anyway, it is what it is ... here's a brief summary for the changes since 1988 to complete that survey.

    1988 to 1995 _ The trends mirror the previous eight years. Most years have seen an average decrease of about -.075 C. Well known record highs in 1989, 1990 and 1995 include some slight changes (1 Aug 95 is down 0.1 to 24.8) and some remain constant (3 Aug 1990 24.4). Nov 1994 has lost 0.2 overall and now has the average of 9.9 C. This interval saw changes to 1815/2922 days; most are in the range of 0.1 to -0.3. 

    1996 to 2003 _ Similar trends continued, the average change to the temperatures in this interval was -.076 C. The eight years involved all dropped roughly similar amounts although 2000 had a decrease of -0.11 and 2001 only -0.04. The record highs in Aug 2003 have been left alone generally, one day (not quite a record) in the hot spell goes up 0.1. 

    2004 to 2011 _ A change of trend occurs around 2005; 2004 on average cooled by -0.06 C similar to past thirty years, but in 2005 the change was much smaller and starting in 2006 the annual changes are positive, although in the range +0.03 to +0.04 C. July 2006 has now gone up 0.1 on average to 19.8 C. Its record high for 19th July is up 0.1 also to 24.6 now. Some of the warmth in Jan 2007 and May 2008 have 0.1 added on now. Most of the colder days through Nov-Dec 2010 are unchanged, notably the record daily values. April 2011 is generally 0.1 warmer than before. 

    2012 to present _ This trend of adding small amounts continues but a slight reversal occurs with Dec 2015 which on average has lost 0.1 (as did its warmest day 19th Dec down from 13.1 to 13.0) and it now has the monthly average 9.6 C. On an annual basis the changes remain similar to the period 2006-11, with all ten years 2012 to 2021 showing an average increase in the .02 to .06 C range. See previous note made for 1948 heat concerning top three daily means which have been re-ordered so that 25 July 2019 is now first (25.3) and 12 Aug 2020 is second (25.2) with 29 July 1948 third now (25.1). The record high daily value on 30 March 2017 has been boosted by 0.1 and is now 15.2. Outlier warm day 31 Oct 2014 is reduced 0.2 and sits at 16.7 now instead of 16.9. Warmer days as well as the entire month of Nov 2015 also downgraded 0.1 C. Record mild days late Jan 2016 are left alone. The warm spell in late Feb 2019 has seen increases of 0.1 or 0.2 to most days. More recently, these changes were made: 14.4 on 31 Mar 2021 up 0.1, 21.4 on 8 Sep 2021 unchanged, 12.9 on 31 Dec 2021 unchanged, 12.7 on 1 Jan 2022 up 0.1. 

    This is a very incomplete summary that relates some of the trends and more significant outliers of the changes made. It has not examined changes to max or min, just mean daily temps. While the data base may have been largely tweaked rather than changed substantially, it will take a bit of time to get used to the new order especially where old records have a somewhat different ranking. 

    Edited by Roger J Smith
    • Like 3
    Link to comment
    Share on other sites

    Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire
    Posted (edited)
    15 hours ago, Weather-history said:

    Winter 2015-16 is the mildest winter on that list ahead of 1868-89

    Wow, that was a very long and very mild winter!!  Must have been dreadfully depressing for cold winter lovers and heat seekers!  

    Edited by Don
    Link to comment
    Share on other sites

    Posted
  • Location: Irlam
  • Location: Irlam
    7 hours ago, Don said:

    Wow, that was a very long and very mild winter!!  Must have been dreadfully depressing for cold winter lovers and heat seekers!  

    Oops,  a morph of 1868-69  1988-89

    • Like 1
    Link to comment
    Share on other sites

    Posted
  • Location: Manchester
  • Location: Manchester

    Interesting to see that summer 2018 is quite considerably warmer overall after the adjustments. Has this affected where it ranks in the warmest summer list at all?

    Link to comment
    Share on other sites

    Posted
  • Location: Dublin, Ireland
  • Weather Preferences: Cold, snowy winters and warm, sunny summers
  • Location: Dublin, Ireland
    2 hours ago, Scorcher said:

    Interesting to see that summer 2018 is quite considerably warmer overall after the adjustments. Has this affected where it ranks in the warmest summer list at all?

    Third place now instead of fourth, behind only 1976 and 1826. In the legacy CET, 1995 was the 3rd warmest.

    • Like 2
    • Thanks 1
    Link to comment
    Share on other sites

    On 11/05/2022 at 20:10, Roger J Smith said:

    Just added some comments about the 1948 hot spell, 29th July has dropped out of a tie for hottest day (with 25-07-2019) and has also fallen below 12 Aug 2020 into third place. That plus the 1869-2016 switcheroo will no doubt give fuel to any small fires of "data massaging to support climate change" as they remove two talking points about older extremes of warmth. Nothing much they could do to obscure May 1833 or June 1846 however.

    Do you really think that the updated CET record is part of a conspiracy to support climate change?   There is more than enough evidence in the legacy version of the CET to show that Britian is getting warmer.

     

     

    Link to comment
    Share on other sites

    Posted
  • Location: Islington
  • Weather Preferences: Freezing cold snowy winters & unsettled summers.
  • Location: Islington
    8 minutes ago, Greyhound81 said:

    Do you really think that the updated CET record is part of a conspiracy to support climate change?   There is more than enough evidence in the legacy version of the CET to show that Britian is getting warmer.

     

     

    I don’t think you understand the context of what he said - he was saying this will likely be a talking point to fuel some peoples opinions, not that this was his opinion. 

    Link to comment
    Share on other sites

    Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    my question is why and how are the changes being made..surely the records are what they are..are they saying the way they were recorded has been wrong or misread all these years..like going into old cricket cards from the past and adding or subtracting runs and thus potentially changing the result.

    • Like 2
    Link to comment
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
     Share

    ×
    ×
    • Create New...