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UK Summers Back To Normal

September 5, 2012

By Paul Homewood

 

Mean temperature Summer UK

Figure 1

Yes, that was it, the English summer has ended. If you blinked, you may have missed it!

 

 

Temperature

Mean temperature averaged 13.9C in the UK as a whole, well down on the long term 1981-2010 average of 14.4C. Since 2006, the average summer temperature has been below average, running at 14.3C.

In terms of ranking, 2012 comes in at the 54th warmest since 1910. The Central England Temperature series shows this summer as 15.2C (higher than the whole UK, as it excludes the colder Scotland and Wales). Figure 2 illustrates just how unremarkable English summers have been lately, and not just in the last couple of years. In the 354 years since the series started, there have been 177 summers that were warmer than this year, and the average summer temperature since 1659 has actually been warmer, at 15.3C.

CET SUMMER TEMPS_htm_9b0ac8

Figure 2

The list of the warmest summers, below, reinforces the point.

 

Year Mean Temperature
1976 17.8
1826 17.6
1995 17.4
2003 17.3
2006 17.2
1846 17.1
1983 17.1
1781 17.0
1911 17.0
1933 17.0
1947 17.0

 

Rainfall

 

Rainfall Summer UK

Figure 4

 

Despite all of the alarmist predictions of record rainfall earlier in the summer, the seasonal total of 370.7mm was below the record set in 1912 of 384.4mm. Although the Met Office data for the UK only goes back to 1910, the Hadley Centre do produce a regional precipitation series for England & Wales, which runs from 1766, as shown in Figure 5. In this series there have been three wetter summers, namely 1912, 1879 and 1829. Figure 6, though, gives a better idea of trends, being based on a ten year running average.CET RAIN SUMMER_htm_m6804245e

Figure 5

CET RAIN SUMMER_htm_11493fa6

Figure 6

 

There has been a declining trend pretty much throughout the 20thC, which bottomed out in the late 1990’s. Since then, however, the trend has been rising back to the sort of levels seen in the 19thC. (The average from 1766-1900 was 236mm, whilst the 20thC average was 216mm. The average for the last decade amounts to 251mm.)

 

UK Government Forecasts

Earlier this year, the UK government published its “Climate Change Risk Assessment”, which forecasts by 2080 :-

1) An increase in summer temperatures of between 1C and 8C.

2) A projected change in average summer rainfall volumes ranging from a decrease of about 60% to an increase of about 10%.

Perhaps somebody ought to tell them to go back to the drawing board.

10 Comments
  1. Ray permalink
    September 5, 2012 8:17 pm

    The fans of “climate change” must be in a bit of a quandary as far as rainfall is concerned.
    While the long-term trend in England & Wales is down, the short-term is up. No doubt both of these will be blamed on “climate chaos”, when all it’s probably just normal climate variation.
    The number of days with over 10mm of rain this summer, in England & Wales was 7, the same as in 1954, 1980 and 1989 and the current 30 year ma is 3.33, lower than the peak 30 year ma of 4.23, reached in 1974. These figures are based on my own count of the HadUKP daily figures, which unfortunately only go back to 1931.

    • September 5, 2012 9:20 pm

      I came to similar conclusions when I looked at the heaviest rainfalls at four stations – Heathrow, Bradford, Aberporth and Shawbury, with data back to 1951. There was no pattern of increasing intensity of rainfall, except at Bradford.

      Are Heavy Rainfalls On The Increase In The UK?–Part II

      • Ray permalink
        September 6, 2012 4:32 pm

        I first got interested in this aspect of “climate change” after reading the following press released, related to some research done by scientists from Durham University, which claimed that the increased number of “extreme rainfall events” since 1961 was evidence of “climate change”.
        http://www.ncl.ac.uk/press.office/press.release/item/?ref=1157358561
        Personally I find it incredible that any scientists could make this claim, based on such short-term data.
        A certain amount of “cherry picking” seems to have taken place in this research. While the probability of an “extreme rainfall” event was found to have increased by 4 times in Scotland and 2 times in N.England, the frequency actually decreased in S.E. England, but “further analysis” showed that region was experiencing a greater frequency of “smaller extreme rainfall events”.
        From what UKMO data I have looked at, it is likely that such events have increased, but that only represents a return to conditions which existed prior to the 1950’s, 1920’s and possibly in the late 19th century, but unfortunately daily rainfall figures only go back to 1931.

      • September 6, 2012 4:53 pm

        Certainly the 60’s and 70’s were relatively dry, which would logically affect the trend.

        Even then, taking average rainfall/rainday, there seems to be little trend of any kind except in the North East.

        Will UK Floods Get Worse?–Part II

  2. Ray permalink
    September 6, 2012 5:17 pm

    It is interesting that you concluded in the other article that lower annual rainfall correlates with lower rainfall per rain day.
    I have found that high annual rainfall correlates with the number of “heavy rain days”, i.e. those over 10mm, which I suppose is logical. From this it is possible to estimate the likely number of “heavy rain days” over the period covered by HadUKP monthly rainfall figures, as far back as 1766 for England & Wales and until 1873 for the regions.
    It is some time since I did the work on “heavy rain days”, so I need to update it. However I find that the daily rainfall figures (at least in the case of the NE) have changed as far back as 2006, even though I did the work in 2010, so the figures will have to be re-calculated.

  3. Stephen Wilde permalink
    September 6, 2012 8:14 pm

    At the moment the favoured jetstream track in summer is across the UK.

    When the Earth is warming the tracks go to the north and the UK is drier.

    When the Earth is cooling the tracks go across the UK or to the south in summer. If they go to the south then the UK can also be drier during a cooling phase.

    So, whether the subtropical highs are dominant or the polar highs are dominant the UK’s ranfall depends on where the boundary lies between the subtropical and polar high pressure systems.

    The Earth is currently in a transition phase between warming and cooling hence the cessation of a clear warming signal for the past 15 years.

  4. Rosco permalink
    September 6, 2012 9:21 pm

    I live in a climate where we already have that frightening scenario – a summer average of around 25 degrees C – actually our year round average is nearly 8 degrees C above Englands summer average.

    Maybe that’s why so many Brits migrate here and swim at the beaches year round ?

    As for ranifall – one day in March we had the total rainfall for the summer in one hour – no that is not a joke – a bit extreme though.

    We emerged from a decade of below average rainfall – drought over a lot of the continent – to 3 years of increasing rainfall with the last 2 being the wettest since 1974 – a major flood year.

    We have also had a few years where it hs been cooler than for many years and the highest snowfalls for many years despite CO2’s best efforts.

    It all sounds like weather to me.

  5. Billy Liar permalink
    October 7, 2012 5:58 pm

    From the Reading University Department of We Haven’t Got a Clue comes these gems:

    Dr Peter Stott, a climate scientist at the University Of Reading and co-author of the paper, said: “The paper is saying there is a significant human influence on global rainfall patterns and this includes an increase of precipitation north of 50 degrees northern latitude, an area that includes the UK.

    “In the UK wetter winters are expected which will lead to more extreme rainfall, whereas summers are expected to get drier.

    Source: http://www.telegraph.co.uk/science/science-news/3301412/Man-made-global-warming-increases-rainfall.html

    Recent warming in the Atlantic Ocean is the main cause of wet summers in northern Europe, according to a new study. A cyclical pattern of rising and falling ocean temperatures is seen as a major influence on our weather. Scientists say the current pattern will last as long as the Atlantic warming persists.

    The study was led by Professor Rowan Sutton, director of climate research at the National Centre for Atmospheric Science at the University of Reading.

    Source: http://www.bbc.co.uk/news/science-environment-19848112

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