Monthly Summary - July 2011

   July was in many ways an odd month. It was undoubtedly cool, but day-time max' temps were relatively high (just above the average for the last four years) and upto the 20th it would have seemed like being another very wet July. But then the last week was more than reasonable and overall rain only fell on 13 days in the month. Anti-cyclonic periods tended to be short lived and hence so was the settled weather, cyclonic conditions being the more common through the month. But it will be the number of cold nights that will set July apart from any other.

   It should also be said that the month started well and the first five days were all quite warm and sunny. It was after this and then upto the 20th that it all became a little bit mixed with rain fairly frequent. It should be remembered that July does tend to be a cyclonic month and hence rain is a frequent visitor (the previous four July's all recorded in excess of 100mm of rain and are perfect examples of this), but expectations for 'Mid Summer' are often quite different to the reality.

   So days 1 - 5 were all decent, a ridge of high pressure had begun to extend over the Uk on the 1st and with rising pressure of polar origins, it was unseasonally cold and at 0.8°c just avoided a ground frost. The 1st at 3.2°c (37.8°F) was the months coldest night. By the 2nd an 'Area of High Pressure' (AHP) (1025 MB) was dominant over the UK and things became quite settled. The 2nd attained 20°c, as did the the next three days, with the months warmest day, 23.8°c (74.8°F) coming on the 4th. The 3rd may have been warm, but the 4th was hot.

   The nights of the 2nd and 3rd were still cold though, 4.7° and 4.8°c, but then the 4/5th brought the months warmest night at 13.5°c and marked a change in the weather.

   By now I was in the mountains of Torridon and enjoying a fine week of weather, but back here in Cumbria that AHP gave way as a slow moving 'Area of Low Pressure' (ALP) moved in from the Atlantic and so came the rain. In the early hours of the 6th the rain was heavy and continued through the morning giving a total of 15.1mm. Tea-time on the 8th saw some very heavy showers and the rain rate reached 115.2mm/per hr in one particularly heavy shower and deposited 12.3mm in total.

   We then entered another more settled phase from the 10-14th with a run of five dry days as a slack AHP (1027) sat over the UK, but that never really fully established itself. Initially that AHP was centred SE of Iceland and by the 13th-14th this was a weak ridge extending North from the Azores. Settled and dry but the warmest temp' in this period was just 21.4°c on the 14th. The ridge of HP was responsible for a NE'ly flow and this helped to keep the days feeling comfortable and not too hot or humid.

   From the 15th an ALP became dominant throught to the 21st and which was quite unseasonal. On the 15th we were inbetween ALP lying in the Atlantic and one over N.Germany with weather fronts making progress East from the Atlantic and which brought 8.6 mm of rain in the evening. Come the 16th the ALP had deepened (to 990 MB) and was NW of Scotland and tracked SE with a series of fronts moving West to East and these brought another 12.9 mm of rain and was the months wettest day.

   That ALP (985) on the 17th was now East of Scotland and had an occluded front spiralling around it and created a day of intermittent rain which brought another 7.3 mm. The 18-19th saw further showers as the ALP still sat to the East of the UK but was now introducing an E-NE'ly flow and cooler conditions. The 20th was the months coldest day at 15.7°C (60.3°F) and was a day of rain (8.8 mm).

   By the 20th we had had 68.8 mm of rain and we seemed all set to make it five successive July's with over 100mm of rain - but then things improved.

   The improvement was graudual, we still had a N'ly flow and temps were pegged back and cloudy but bright conditions prevailed as opposed to sunny skies. Come the 22nd a ridge of HP (1025) was extending North from the Azores to western parts of the UK and remained until the 24th. Still with that N'ly flow through this period, but the 23-24th saw decent days with plenty of sun (especially (24th). The nights though saw the temp's get quite chilly, the early hours of the 23rd saw a minimum of 3.3°c and the 24th 4.2°c.

   That ridge of HP was replaced on the 25th as an ALP (1008) south of Iceland with its associated weather fronts trailing just West of the UK brought cloudier conditions, but now the temperature was rising slightly as the airflow shifted back to the South. The 26th attained 20°c as did every day, apart from the 29th, to the months end. The 27th was a lovely day as we sat in a slack AHP, although weather fronts were in the Atlantic and moving East and brought cloudier skies on the 28th.

   But come the 29th, which started cloudy and had a little rain first thing as a weak front moved through, high pressure began to build again and the month ended warm and settled. Even then the last two days were different as the 30th was hot and sunny (22.3°c) but the 31st was was cloudy and humid at 20.5°c

   So the month was the coldest July recorded at this site, with seven days recording temperatures below 5°c, the three previous July's had a combined total of two! This saw the mean minimum temperature for the month at a very chilly 8.4°c. But then 20°c was attained eleven times which is the combined total for the last two years!!

   Rainfall totalled 69.6 mm for the month, with rain recorded on 13 days of which 10 were 'Wet days' (1.0mm +).

   The Mean Temperature for the month was 13.85°c+         --      The Mean Max' was   19.27°c   --    The Mean Min'   8.43°c.

   We had 0 Air Frosts in the month (year 30)      --      Grass frosts totalled 0 (year 50).

   The 30 cm soil temp ranged from 15.4°c on the 1st      to      17.3°c on the 31st      --      with a monthly mean of 16.5°c


   * July 2011 rainfall was 50.4% of the July average for 2007 - 2010

   * July 2011 was 0.76°c colder than July 2010   --   0.99°c colder than 2009 +

  * The 3 month mean for May/June/July 2011 is                   TEMP'    12.22°c         --          RAIN    248.0 mm

* May/June/July 2010 was TEMP'    12.59°c -- RAIN    155.6 mm

* May/June/July 2009 was TEMP'    12.87°c -- RAIN    311.2 mm

* May/June/July 2008 was TEMP'    -- RAIN    212.5 mm


* 2011 To date TEMP'    8.58°c -- RAIN    668.9 mm

* 2010 Jan - July TEMP'    7.50°c -- RAIN    314.2 mm

* 2009 Jan - July TEMP'    8.67°c -- RAIN    650.7 mm

* 2008 Jan - July TEMP'    -- RAIN    723.7 mm

   + Met office figures for July show that NW England/N. Wales had a mean temp' of 14.1°c, this being -0.8°c colder than the reference period 1971-2000 (-0.3°c colder than reference period 1961-90)


JANUARY 2010    FEBRUARY 2010    MARCH 2010    APRIL 2010    MAY 2010    JUNE 2010    JULY 2010    AUGUST 2010    SEPTEMBER 2010    OCTOBER 2010    NOVEMBER 2010    DECEMBER 2010   

JANUARY 2011    FEBRUARY 2011    MARCH 2011    APRIL 2011    MAY 2011    JUNE 2011   

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