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graphs CLIMATE-UK.COM'S REVIEW OF THE BRITISH METEOROLOGICAL SCENE
MONTHLY SUMMARY
No. 644 For AUGUST 2009
EXCEPTIONALLY WET IN SCOTLAND AND NORTHERN IRELAND; DRY AND WARM IN EAST ANGLIA AND THE SOUTHEAST
Text Box: A changeable southwesterly type affected the British Isles throughout the month. There was a marked cyclonic bias over Ireland and Scotland which were consequently very wet, but pressure was close to or slightly above the norm for long periods in southeast England where it was generally dry and warm. This month was the fifth most southerly August in 137 years of records.

A cold front advancing eastwards across the country on the 1st resulted in a cloudy day with outbreaks of rain, but it was bright and warm for much of the day east of the Greenwich meridian with 26C reached locally in Norfolk. The next two days were mostly fair, but a deep depression wound up to the west of Ireland between the 4th and 6th and the associated active cold front made slow and erratic progress eastward across the UK. There were lengthy outbreaks of heavy rain, thundery in places, especially on the 4th (58mm at Evershot, Dorset) and the 6th (60mm at Holbeach, Lincs, and 52mm at Royston, Herts). Ahead of the cold front the temperature reached 29C at East Anglia and the Southeast on both the 5th and 6th.

Between the 7th and 13th pressure was relatively high over southern Britain, although a filling depression tracked eastwards across northern England on the 9th/10th. During this period much of England and Wales was rather warm with variable amounts of sunshine and small amounts of rain, but the weather remained unsettled in Scotland and Northern Ireland with further bursts of heavy rain. A brief respite overnight 13th/14th gave a clear, cold night in Scotland with an air minimum of 0.4C at Aberfeldy (Perthshire). A vigorous Atlantic depression travelled slowly past northwest Scotland between the 14th and 16th bringing prolonged heavy rain to northern and western regions, while further south it became cloudy and breezy although many places remained dry.
Text Box: Another deep depression tracked slowly past western Ireland and western Scotland between the 17th and 20th, maintaining the unsettled, very wet and often windy weather over Scotland, Northern Ireland, northwest England and north Wales, but a southerly airstream drew very warm air across central and eastern England, with 30.3C reached at Broadness (Kent) on the 19th. At Eskdalemuir (Dumfriesshire) 78mm of rain fell on the same day, with 165mm from the 14th-19th inclusive and a further 100mm during the subsequent week. After a couple of cooler, breezy days with scattered showers, it became very warm again in central and eastern districts on the 23rd with highs of 25-28C, and the warmth continued on the 24th in East Anglia and Kent.

Most of the last week was cooler and unsettled. There were heavy showers and local thunderstorms at times, and on the 26th most parts of the country were cloudy and rather windy with rain at times, courtesy of a depression containing the remnants of hurricane Bill, and it was windy again on the 28th with a maximum gust of 55kn at Mumbles (Glamorgan). Bright, warm weather returned to eastern and southern England on the 31st, but it was again wet in the west and north.

Mean maximum temperature ranged from 1.5-2.0degC above the 1971-2000 average in East Anglia and southeast England to about 0.5degC below in western Scotland. Mean minimum temperature was 0.5-1.5degC above in all regions. Rainfall percentages ranged from less than 25 in the eastern part of East Anglia and Kent, where it was the driest August since either 2003 or 1995, to over 300 in southwest Scotland where some new records were established. Sunshine aggregates were 10-15 per cent above normal in eastern districts, but 20-40 per cent below in western Britain and Northern Ireland.
                                                                                                                                             
    TEMPERATURE   SUNSHINE   RAINFALL        
                                                                                                                                     
                                                                                                                                     
                                  Highest and lowest totals             Highest and lowest totals        
                                  on record for month    
Maximum fall in 24 hrs
   (beginning 09 h)
        on record for month    
Days with snow or sleet
 
Days with fog
(Vis <220 yards at 09 h)
 
                                                                                         
     
Difference from average
   
Difference from average
 
Highest maximum
   
Lowest minimum
   
No. of days with grass
  minimum below 0C
   
Days of no sunshine
 
Maximum duration
       
First year of record
         
Days of no rainfall
 (0.1 mm or less)
         
First year of record
         
Days with thunder
     
  PLACE  
Mean Maximum
   
Mean minimum
             
No. of air frosts
       
Total for month
                   
Total for month
                   
                               
% of average
                   
% of average
                 
                                                                     
                                   
Highest
   
Lowest
 
Year
             
Highest
   
Lowest
 
Year
       
             
Date
   
Date
         
Date
         
Year
         
Date
         
Year
           
                                                                     
    C     C     C     C           Hrs     Hrs       Hrs     Hrs       mm     mm       mm     mm          
                                                                                                                                             
  *Hampstead   22.2   +1.1   13.8   +1.0   27.5   19   10.5   29   00   00   00   10.1   19   155   081   1910   282   1995   097   2008   22   45.3   06   055   076   1910   184   1975   02   1995   00   00   00  
  Thorney Island   21.4   -0.4   14.0   +0.6   24.5   06   10.1   18   00   00   00   12.6   19   178   083   1958   303   1976   117   2008   19   04.4   06   016   029   1941   141   1960   04   1976   01   00   00  
  *Wattisham   23.3   +2.3   12.9   +1.3   27.9   06   07.3   22   00   00   00   13.2   19   206   108   1968   285   1995   122   2008   18   06.0   01   018   032   1960   130   2006   03   2003   02   00   00  
  *Wittering   22.0   +1.6   12.6   +0.6   27.6   19   07.4   22   00   00   00   12.3   19   180   095   1950   258   1995   090   1971   17   29.6   06   044   067   1948   162   2004   03   1983   02   00   00  
                                                                     
  Lyneham   20.1   -0.3   12.5   +0.6   25.2   19   09.2   29   00   00   02   13.2   08   158   079   1952   297   1995   111   2008   18   15.8   06   039   057   1945   136   1951   02   1995   01   00   00  
  Ross-on-Wye   21.1   +0.2   12.8   +0.6   25.5   11   08.2   22   00   00   04   12.1   08   177   098   1915   307   1995   107   1922   18   05.5   04   021   033   1859   202   1878   04   1936   03   00   00  
  *St Athan   19.0   -1.1   13.9   +1.3   23.0   19   08.7   08   00   00   05   13.3   07   144   068   1954   325   1995   089   2008   12   22.4   20   069   079   1954   202   1997   22   1955   01   00   00  
  Culdrose   18.2   -0.8   13.5   +0.4   21.4   11   08.1   08   00   00   05   12.5   07   132   061   1961   312   1976   105   2008   11   10.3   09   053   075   1961   208   1997   04   1981   00   00   00  
                                                                     
  *Edgbaston   20.2   -0.7   13.3   +0.5   25.2   19   09.9   29   00   00   01   11.9   08   138   074   1887   282   1995   085   1896   17   13.5   04   045   081   1887   173   1912   06   1940   02   00   00  
  *Valley   17.9   -1.1   13.7   +0.9   19.8   10   10.3   22   00   00   03   12.1   05   136   067   1946   291   1976   086   2008   11   23.4   19   103   147   1941   210   1956   05   1959   00   00   00  
  *Woodford   20.0   +0.2   12.3   +1.0   24.0   19   08.5   14   00   00   00   10.8   22   121   070   1945   284   1995   079   2008   09   08.0   28   053   064   1942   201   1956   07   1976   01   00   00  
  *Watnall   20.9   +0.5   12.8   +0.8   26.3   19   08.7   29   00   00   03   12.7   08   151   080   1948   261   1995   098   1963   14   16.2   06   056   086   1942   154   2004   04   1995   02   00   00  
                                                                     
  *Leeming   20.7   +0.6   12.2   +0.8   26.2   19   08.3   26   00   00   01   09.3   02   141   085   1945   246   1995   086   2008   13   08.6   24   043   047   1945   165   1971   07   1947   02   00   00  
  *Boulmer   19.8   +1.8   12.0   +0.5   24.5   19   07.8   25   00   00   03   09.8   02   122   074   1945   273   1995   072   2008   09   15.6   09   047   058   1945   199   1956   03   1947   00   00   00  
  *Eskdalemuir   17.4   -0.4   10.7   +1.4   21.9   06   05.1   13   00   00   07   08.3   24   089   061   1911   260   1947   041   2008   05   78.0   19   * 393   322   1911   345   1985   01   1947   01   00   00  
  *Bishopton   18.3   -0.9   11.8   +1.1   22.2   10   07.8   13   00   00   04   09.5   24   116   073   1921   254   1995   068   2008   04   39.0   14   211   254   1921   213   2004   00   1947   00   00   00  
                                                                     
  *Leuchars   19.2   +0.6   11.4   +0.7   22.5   08   06.9   25   00   00   03   13.8   02   168   096   1922   242   1995   095   2008   09   14.0   14   082   119   1922   213   2004   07   1955   00   00   00  
  *Dyce   18.5   +0.5   11.7   +1.6   21.0   08   08.0   08   00   00   03   12.6   06   129   081   1941   257   1947   076   1963   10   13.8   14   051   064   1941   162   1962   00   1947   00   00   00  
  *Stornoway   16.5   +0.2   11.5   +1.2   19.6   04   09.5   13   00   00   03   11.3   24   096   064   1880   262   1899   065   2006   02   12.2   27   122   165   1943   203   1982   13   1947   00   00   00  
  *Aldergrove   18.5   -0.1   12.5   +1.4   20.5   04   09.3   30   00   00   02   09.3   05   102   067   1927   276   1976   061   2008   04   48.2   19   176   229   1927   181   2008   09   1947   00   00   00  
 
                                                                                                                                             
  Stations marked with an asterisk record sunshine electronically; comparisons      
  with earlier records are therefore somewhat speculative. Thorney Island's     * New highest  
  sunshine figures are from a nearby site.