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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 655       For     JULY    2010
   DULL AND WET IN ALL WESTERN REGIONS;  DRY AND WARM IN EAST ANGLIA AND THE SOUTHEAST
Text Box: Westerly and southwesterly winds prevailed for much of July and the mean monthly sea-level pressure was below normal in all regions. It might, therefore, come as something of a surprise that East Anglia and Southeast England experienced a dry and very warm month. By contrast most western regions were dull and wet with rather cool days and rather warm nights. A vigorous depression, unusually deep for July, tracked slowly northwards to the west of Ireland during the first three days, and a further very deep depression headed northeast then north towards Iceland on the 7th-8th. Over the next few days shallow secondaries moved northeastwards across the British Isles, followed overnight 10th/11th by a more active disturbance. Thanks to a generally southerly flow, the first three days of July were generally warm - very warm in central and eastern England with 29.9°C at Swanscombe (Kent) on the 2nd - although rain fell heavily in some northern and western parts of the country on both the 1st and 3rd. A notably high minimum of 20.2°C was logged overnight 1st/2nd at Olympic Park (London). From the 4th to the 7th temperatures were somewhat lower and there were further periods of rain, heavy at times, in the north and west, although amounts of rain in the south and east were generally small or non-existent. Tyndrum (Stirlingshire) collected 58mm in 48h on the 3rd/4th. It became very warm again with long sunny spells between the 8th and 11th in eastern, midland and southern counties of England: highs on the 9th included 31.7°C at Swanscombe and 31.4°C at Writtle (Essex), and on the 10th 30.9°C at Swanscombe and 30.8°C at Santon Downham (Norfolk). Further appreciable falls of rain occurred in the north and west; during the first ten days of July 153mm of rain fell at Broadford (Skye). Pressure was almost uniform over the British Isles on the 12th and 13th, but another deep depression tracked northeast then north across the UK on the 14th/15th followed by a vigorous secondary on the 15th/16th. A transitory ridge crossed the country on the 17th, then a moist southwesterly flow developed for a couple of days, before a relatively shallow complex low settled across the country between the 20th and 22nd. The 12th-17th was the coolest phase of the month although in southern and eastern England temperatures were scarcely below the average. After a relatively quiet day on the 12th, rain spread across most of the UK on the 13th and there were further
Text Box: outbreaks of rain on the 14th and 15th, heaviest in western regions; 74mm of rain fell at Auchincruive (Ayrshire) on the 14th, and 53mm at St Angelo (Co Fermanagh) on the 15th. It also became very windy with gusts of over 50kn widely recorded in Wales and the West Country; gusts to 73kn were logged at Aberdaron (Caernarfon) on both the 15th and 16th. The maximum on the 14th was just 11.2°C at Braemar (Aberdeenshire) and 11.5°C at Aviemore (Inverness-shire). Rain returned to western and northern regions from late on the 17th till the 21st, and on the 20th alone 68mm fell at Hawarden (Flintshire) while appreciably more may have fallen in the Wrexham area, but once again it became fine and very warm in East Anglia and the Southeast especially on the 19th and 20th. Heavy showers with local thunder affected England and Wales on the 21st and 22nd, and the 23rd was particularly cold in northeast England with highs of 11.2°C at Loftus (N.Yorks) and 11.4°C at Albermarle (Northumberland). Capel Curig (Caernarfon) collected 205mm of rain between the 13th and 22nd. A ridge of high pressure moved slowly southeastwards across the UK on the 23rd and 24th followed by a rather moist west to northwesterly airstream, but disturbances during the last week of the month were less active than previously.Rising pressure over Scotland on the 23rd resulted in a rare sunny day there - Lerwick (Shetland) logged 16.0h of bright sunshine - but for most of Britain the last week was rather cloudy with occasional, rather sporadic, outbreaks of light to moderate rain, and it was rather warm and humid at times in eastern, central and southern districts. This was a month of marked geographical contrasts. Mean maximum temperature ranged from 2.0degC below the 1971-2000 average in parts of northwest Scotland to 3.0-3.5degC above locally in East Anglia. Mean minimum temperatures were typically 0.5-1.5degC above in all regions, and new July records were established at Valley and Bishopton. It was the fourth consecutive very wet July in most western and northern regions, but it was a very dry month in parts of East Anglia and the Southeast, percentages ranging from 275 locally in western Scotland, Cumbria and Snowdonia to 20 in the London and Cambridge districts. Capel Curig recorded 363mm but Kew Gardens and Cambridge just 10mm. Sunshine percentages ranged from around 140 in Shetland and 125 in east Kent to 50-55 at some sites in southwest Scotland, northwest England and the north Midlands; totals varied between 260h at Guernsey airport and 69h at Eskdalemuir; it was the dullest July on record at Woodford (Gtr Manchester), Aldergrove (Co Antrim) and Eskdalemuir (Dumfriesshire).
                                                                                                                                               
                       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 0ºC
   
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
           
                                                                       
      ºC       ºC       ºC       ºC             Hrs       Hrs         Hrs       Hrs       mm         mm         mm     mm          
                                                                                                                                               
  *Hampstead   23.9   +2.5   14.3   +1.4   30.4   09   11.3   30   00   00   00   10.8   09   163   093   1910   321   1911   109   1913   23   03.5   14     012   021   1910   193   1924   05   1921   01   00   00  
  Thorney Island   22.2   +0.1   14.3   +1.0   27.0   26   10.3   04   00   00   00   11.6   21   188   088   1958   336   2006   153   1978   17   08.0   30     023   045   1941   122   1945   06   1949   00   00   00  
  *Wattisham   23.8   +2.8   13.3   +1.6   30.6   09   07.8   06   00   00   01   14.5   10   166   092   1968   295   1976   131   1978   17   10.6   27     055   105   1960   101   1987   05   1977   02   00   00  
  *Wittering   22.5   +2.0   13.3   +1.3   29.1   09   09.6   18   00   00   02   12.4   03   158   088   1955   283   2006   115   1965   21   07.8   12     037   068   1955   153   2004   06   1977   01   00   00  
                                                                       
  Lyneham   22.2   +1.3   12.9   +0.8   26.9   09   09.6   06   00   00   00   12.9   03   154   075   1952   314   2006   129   1965   10   10.2   16     039   075   1945   149   2007   04   1955   01   00   00  
  Ross-on-Wye   22.0   +0.9   13.2   +0.8   25.5   10   08.5   06   00   00   00   11.8   05   155   088   1915   311   2006   095   1944   16   14.5   15     049   092   1859   197   1872   06   1935   00   00   00  
  *St Athan   20.2   +0.2   14.2   +1.7   24.5   19   10.7   06   00   00   01   12.3   05   154   076   1954   319   1955   131   1965   13   13.6   14     058   081   1954   188   2009   13   1977   00   00   00  
  Culdrose   19.1   +0.4   13.9   +1.1   22.1   26   11.0   06   00   00   01   12.5   21   156   074   1961   306   1971   117   1991   14   18.6   01     049   082   1961   197   2009   05   1999   00   00   00  
                                                                       
  *Edgbaston   21.1   -0.1   13.7   +0.8   25.4   09   11.4   16   00   00   00   08.3   10   114   067   1887   285   1990   067   1888   19   07.2   15     026   056   1887   183   2007   07   1911   01   00   00  
  *Valley   18.1   -0.6   13.5   +1.0   22.3   26   11.2   13   00   00   06   12.2   03   121   064   1946   341   1955   115   1986   10   21.6   19     * 127   222   1941   114   1957   09   1983   00   00   00  
  *Woodford   20.3   +0.6   12.9   +1.6   26.0   10   07.4   24   00   00   03   08.4   05   * 082   051   1945   280   2006   102   1954   09   15.8   19     069   090   1942   187   1973   10   1999   00   00   00  
  *Watnall   21.2   +0.7   13.2   +1.2   26.6   10   09.9   06   00   00   03   10.2   03   116   065   1948   273   2006   087   1965   18   10.8   14     037   069   1942   148   1973   11   1982   01   00   00  
                                                                       
  *Leeming   20.9   +0.6   12.1   +0.4   26.4   10   07.0   23   00   00   01   10.8   03   130   082   1945   276   2006   091   1965   17   30.2   20     069   136   1947   139   2009   09   1984   00   00   00  
  *Boulmer   19.6   +1.5   11.8   0.0   23.1   09   07.8   23   00   00   00   11.5   03   117   069   1945   268   1955   105   1957   14   21.4   20     097   167   1945   155   2009   07   2006   00   00   00  
  *Eskdalemuir   17.0   -0.8   10.0   +0.9   19.7   20   03.3   23   00   00   06   10.1   29   * 069   048   1911   266   1989   075   1931   05   33.6   01     246   230   1911   269   1988   25   1913   02   00   00  
  *Bishopton   18.4   -0.7   12.1   +1.4   21.3   02   09.4   06   00   00   06   10.9   29   095   057   1921   297   1989   086   1931   03   24.4   21     * 155   225   1921   147   1988   11   1984   02   00   00  
                                                                       
  *Leuchars   19.4   +0.6   11.3   +0.5   23.3   02   07.3   24   00   00   03   12.2   07   160   089   1922   262   1955   091   1931   12   40.2   14     124   191   1922   181   1940   13   1983   01   00   00  
  *Dyce   18.3   +0.2   10.7   +0.6   22.6   18   04.3   23   00   00   03   12.5   12   137   088   1941   263   1955   078   1968   12   26.8   14     108   145   1941   198   1957   13   2003   01   00   00  
  *Stornoway   16.0   +0.2   10.9   +0.6   18.2   28   06.6   22   00   00   04   10.6   10   106   081   1880   227   1917   057   1939   03   11.4   03     108   151   1943   165   1988   14   1955   01   00   00  
  *Aldergrove   19   +0.5   12.4   +1.3   22.9   01   06.4   23   00   00   04   09.9   23   * 080   059   1927   274   1955   086   1986   07   29.2   15     106   113   1927   155   1950   12   2000   01   00   00  
                                                                       
                                                                                                                                               
  Stations marked with an asterisk record sunshine electronically; comparisons      
  with earlier records are therefore somewhat speculative. Thorney Island's   * New low record   * New high record  
  sunshine figures are from a nearby site.