Monthly Summary - July 2010

   Oh dear. July is going to get itself a bad reputation for been wet, cool and dull. By that, the safe assumption is that the dry spell has come to an end.

   July saw cool daytime maximum temperatures, although with high night-time minimum temps' the monthly mean temperature is (believe it or not) just about the average. But with close on an average of 91% cloud cover at 0900 Hrs, a highest max' temp' of just 21.3°c (70.34°F), only three days reaching 20.0°c and the fourth successive July to record over 100 mm of rain, the 'height of summer' just never arrived.

   At least the rain felt warm and the grass has returned to its natural green colour, but in my short time of recording, only the month of July has recorded over 100 mm of rain everytime. This July has provided us with 34.3% of the total rainfall to date in 2010.

   And apart from that above, it was often windy, especially during the first half of the month. A maximum gust of 50 mph was recorded on the 16th - not unheard of in July, but very unusual.

   The month's weather was often controlled by cyclonic conditions with low pressure to the fore, either pushing NE from Biscay or the Atlantic route via Eire.

   Just one more slightly depressing note is that the month's mean maximum temperature of 18.01°c (64.4°F) was 1.04°c lower than that of Junes!!

   The 1st was notable for providing us with the month's highest temperature (21.3°c) but after 6 p.m. a frontal system moved north out of the West country bringing with it rain overnight and into the 2nd. Slowly the 2nd brigtened and the 3rd was a fine day, if somewhat breezy. But eyes were cast to a deep low (970 Mb) south of Iceland that was moving east.

   But a low (995) west of Eire was deepening and moved quickly NE, arriving on the 4th, bringing with it more rain (5.8mm) and unseasonally strong winds, gusting to 45 mph.

   The low moved away north of Scotland and the 5th brought cloudy and fresher conditions. An 'Azores high' (1033 Mb) was now trying to push NE, if it could exert itself far enough our way, summer would be back. The 6th saw a ridge of high pressure over the UK, but an area of low pressure with two centres (998+1003 Mb) sat in the Atlantic pushing warm fronts east and instead of sun we had more cloud. Summer hadn't arrived and that high pressure retreated.

   The 8th saw a large depression SE of Iceland (quite intense for the time of year) slowly moving our way, but it moved North and we did not get its full force - the 8th started cloudy, brightening up and the 9th was a grey and drab affair of drizzle and 3.0 mm of rain.

   10th + 11th were poor days. 12.4 mm of rain on the 10th with a further 3.0 mm on the 11th which at 16.6°c was also cold. A long frontal system stretching back into the mid Atlantic was sending small wave fronts our way.

   And so it continued, under the influence of low pressure we had poor uninspring days that were never sunny, just cloudy and dull with some rain and then on the 14/15th it got worse.

   15th July, St. Swithins day, do you believe in the folklore? Well it rained and we also had gales. Gusts upto 42 mph as an area of low pressure (992 Mb) sat over the UK and its associated fronts and troughs brought us heavy showers. On the 15th it was a large multi centred area of low pressure with deepest low (988 Mb) in the Irish sea that brought 13 mm of rain and at 0630 hrs winds gusting to 50 mph - In July!!

   Another trend through July and more so in the second half of the month was that evenings tended to brighten up following cloudy days, but never anything to get to excited about.

   Another 9.0 mm of rain came on the 18th on the back of various frontal troughs spreading over NW UK associated to another mid Atlantic low pressure system.

   And then the 19th brought the wettest day (16.6 mm) of the year and the wettest since November. It was also the warmest night of the month at 14.3°c.

   The 22nd saw the month's coldest day at just 15.8°c (60.44°F) and the 23rd saw the coldest night at 4.8°c (40.64°F) with a ground temperature of 3.6°c - this was on the back of a brief spell of Arctic air brough to us by a small ridge of high pressure, but it at least ensured that the 23rd was a sunny day, also dry (St. Swithins folklore dashed) and quite pleasant at 19.2°c.

   At least the last week of the month saw little rain, but the theme was still cloudy and grey days although there was a little brightness at times, but very much a shortage of the that big bright yellow thing in the sky.

   The Mean Temperature for the month was 14.61°c+     - the Mean Max' was 18.01°c and the Mean Min' 11.22°c.

   We had 0 Air Frosts in the month (59 for 2010) and Grass frosts totalled 0 (93 for 2010).

  COMPARISONS:-

   * July 10 rainfall was 72.83% of the July average for 07/08/09

   * July 10 was 0.23°c colder than July 2009 +

   * July saw 22 rain days of which 16 were wet days.



  * The 3 month mean for May/June/July 2010 is            TEMP'    12.59°c         -          RAIN    155.60 mm

* May/June/July 2009 was TEMP'    12.87°c - RAIN    311.20 mm

* May/June/July 2008 was TEMP'    - RAIN    212.50 mm

 

* 2010 TO DATE 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 15.1°c, some +0.3°c warmer than the reference period 1971-2000 (+0.8°c warmer than reference period 1961-90)

   PREVIOUS MONTHS REPORTS

JANUARY 2010    FEBRUARY 2010    MARCH 2010    APRIL 2010    MAY 2010    JUNE 2010   

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