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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 642       For     JUNE    2009
         ALTERNATING WARM AND COOL SPELLS; GENERALLY DRY AND SUNNY EXCEPT 5TH-10TH
Text Box: Easterly winds prevailed during the first ten days and again during the last week, but westerlies and northwesterlies dominated between the 11th and the 22nd. Apart from a cyclonic period from the 5th-10th, pressure was generally above normal. It was the seventh most ‘easterly’ June in 137 years of records. The late-May fine spell continued into early-June with maxima of 24-27°C in southern and western districts and almost unbroken sunshine in many places. The anticyclone responsible had retreated to Iceland by the 3rd, allowing much cooler Arctic air to penetrate from the north and northeast, but it remained warm and sunny in the southwest until the 4th. Falling pressure led to the formation of a complex depression over France on the 5th, and outbreaks of heavy rain affected much of the UK over the 5th and 6th although large parts of western Scotland and Northern Ireland stayed dry. The rain was heaviest in Devon, Somerset, Glamorgan, Gwent and Herefordshire; there were unconfirmed reports of 90-95mm in the Exeter district, and 79mm fell at Ross-on-Wye (Herefs). Throughout these two days a very cold northeasterly flow affected much of the country and on the 5th the maximum temperature was just 6.4°C at Copley (Co Durham). On the 7th a northward-moving occlusion was responsible for heavy thundery rain in many places, and this was followed by heavy showers and thunderstorms; 44mm fell at Chesham (Bucks). Further depressions tracked northeastwards close to southern Britain on the 8th/9th and again on the 10th, maintaining the cool unsettled weather and bringing further substantial falls of rain. Pressure now rose generally, although a depression took up residence for several days off southwest Ireland. The weather became warmer with maxima of 22-25°C in some Text Box: heavy showers and local thunderstorms.On the 17th and 18th a deep Atlantic depression tracked between Scotland and Iceland bringing general rain, heaviest in the hillier parts of western and northern Britain, stronger winds, and a general drop in temperature. There was a renewed pressure rise during the 19th and 20th, although a northwesterly airflow maintained rather cool and cloudy weather. By the 22nd/23rd an anticyclone lay over the UK, thence migrating to Scandinavia bringing a spell of mainly dry and rather warm weather with increasing amounts of sunshine - many places had almost uninterrupted sunshine on the 23rd and 24th. With a brisk easterly airflow developing, highest temperatures were found in northwest Scotland, including 26.9°C at Kinlochewe (Wester Ross) on the 24th. From the 25th onwards the flow veered southeasterly and it became hot and humid with a good deal of thundery activity. One storm dropped 51mm at Edgbaston (Birmingham) on the 26th, and the following day 23mm fell inside 30mins at Hampstead (London). The temperature exceeded 30°C in the London area on the 29th and 30th, with 31.2°C at Heathrow on the 30th; on the same day Wisley (Surrey) reported 31.8°C. Mean maximum temperature was 1.0-2.0degC above the 1971-2000 average in most parts of the country, and mean minimum temperature 0.5-1.5degC above. Rainfall was below the long-term average in most regions, although there were some large individual totals thanks to several localised thundery downpours. Less than 20mm fell locally along the English Channel coast. Aggregate sunshine ranged from 10-20% below normal in parts of eastern Scotland, northeast England and the east Midlands, to 50% above in the Northern and Western Isles and in parts of Northern Ireland. Fair Isle logged 300h of bright sunshine and Tiree 283h.
                                                                                                                                             
                       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   20.8   +1.8   11.2   +1.3   28.4   29   05.9   04   01   00   01   12.2   02   180   107   1910   284   1957   121   1923   21   33.2   27   079   145   1910   136   1971   03   1925   02   00   00  
  Thorney Island   20.2   +0.7   11.2   +0.7   26.3   25   04.5   08   00   00   00   15.8   02   235   115   1958   311   1975   138   1990   21   09.8   06   019   047   1941   111   1971   06   1976   01   00   00  
  *Wattisham   19.7   +1.1   09.8   +0.9   26.4   29   03.1   12   02   00   00   14.9   01   196   107   1968   283   1989   141   1987   17   11.4   10   036   066   1964   125   1980   07   1976   02   00   00  
  *Wittering   19.8   +1.7   10.4   +0.6   28.6   30   04.3   12   01   00   00   15.2   01   189   100   1955   284   1976   096   1987   18   11.6   10   041   078   1955   153   1982   03   1962   04   00   00  
                                                                     
  Lyneham   20.1   +1.6   10.5   +1.2   28.2   29   06.3   07   00   00   00   15.6   02   213   112   1952   306   1957   113   1997   24   07.0   10   024   039   1945   145   1971   03   1962   03   00   00  
  Ross-on-Wye   20.8   +2.0   10.3   +0.5   29.0   29   05.0   12   00   00   02   14.5   24   209   116   1915   318   1925   117   1990   18   55.6   05   103   195   1859   165   1982   00   1925   04   00   00  
  *St Athan   19.1   +1.4   11.6   +1.6   25.4   29   06.8   07   00   00   01   14.9   02   196   100   1954   323   1957   140   1972   20   47.8   06   089   152   1954   151   1954   05   1975   02   00   00  
  Culdrose   18.1   +1.5   11.1   +1.0   23.6   03   03.8   07   00   00   01   15.0   02   255   125   1961   310   1975   133   1997   22   08.6   08   021   036   1961   130   1997   08   1962   01   00   00  
                                                                     
  *Edgbaston   19.5   +1.4   11.2   +1.7   27.4   29   06.5   12   00   00   01   14.0   01   164   110   1887   283   1957   095   1923   16   51.4   26   133   189   1887   183   2007   04   1942   04   00   00  
  *Valley   18.8   +2.2   11.3   +1.2   27.3   29   05.7   12   01   00   02   15.5   24   235   116   1946   305   1975   134   1987   20   11.4   17   043   077   1941   112   1998   01   1942   00   00   00  
  *Woodford   19.5   +1.5   09.5   +0.7   26.2   29   02.0   12   02   00   02   15.8   24   174   102   1945   285   1957   103   1987   11   21.8   10   086   130   1942   174   1987   12   1942   02   00   00  
  *Watnall   19.7   +1.6   10.5   +0.7   29.3   30   05.4   04   00   00   03   15.4   01   158   084   1948   261   1960   103   1987   19   26.4   07   064   123   1942   175   2007   08   1975   05   00   00  
                                                                     
  *Leeming   19.0   +1.0   09.2   +0.2   27.8   30   03.7   09   01   00   00   15.5   01   152   093   1945   298   1957   092   1987   17   22.6   05   038   084   1947   178   2007   09   1976   04   00   00  
  *Boulmer   16.0   +0.2   09.9   +1.5   19.9   22   05.5   18   00   00   02   14.6   01   171   106   1945   261   1957   082   2007   14   06.0   20   029   056   1945   146   1997   09   1976   00   00   01  
  *Eskdalemuir   18.1   +1.8   08.2   +1.4   26.1   02   00.3   12   06   00   00   10.2   02   134   088   1911   276   1957   082   1912   11   20.8   17   080   080   1911   260   1931   13   1992   01   00   00  
  *Bishopton   19.1   +1.5   09.9   +1.3   26.5   01   02.7   12   00   00   01   15.1   01   194   112   1921   279   1995   089   1966   18   11.4   16   037   060   1921   131   2002   10   1988   01   00   00  
                                                                     
  *Leuchars   16   -0.6   09.1   +0.8   24.2   22   03.4   08   04   00   04   15.5   01   158   089   1922   264   1949   075   2007   11   09.6   13   045   095   1922   138   2007   07   1940   00   00   01  
  *Dyce   15.5   -0.5   09.1   +1.3   21.1   29   03.6   08   02   00   03   15.8   01   138   086   1941   245   1970   079   2007   13   15.4   10   059   105   1941   146   1997   14   1982   00   00   01  
  *Stornoway   15.7   +1.4   09.2   +1.1   23.2   27   02.5   11   02   00   01   16.1   28   252   153   1880   278   1970   072   1984   12   11.8   16   036   051   1943   112   1994   15   1982   00   00   00  
  *Aldergrove   18.9   +1.7   10.1   +1.1   25.9   02   04.5   12   00   00   01   15.6   01   227   137   1927   287   1957   103   1980   20   18.8   16   054   076   1927   129   1980   11   1941   01   00   00  
                                                                     
                                                                                                                                             
  Stations marked with an asterisk record sunshine electronically; comparisons      
  with earlier records are therefore somewhat speculative. Thorney Island's      
  sunshine figures are from a nearby site.