July 2013 Summary

In Brief:
A very warm and record-breaking month with mainly dry weather until the last 8 days. 

Temperature: [Minimum]:
The lowest temperature recorded for the month was 13.5 degs C on the night of the 11th/12th.  This is the first month since records began here in October 2003 where the temperature has never fallen below that figure. Previously the highest minimum was 11.5 degs C, recorded in August 2004 and July 2010.

The warmest night of the month was that of the 30th/31st with a minimum of 19.8 degs C, the highest minimum ever recorded at this site.*  Until July 2013 this figure was 19.2 degs C, from July 2006, however that record was broken four times this month - the other three times being every night from the 22nd/23rd to the 24th/25th. 

The average minimum for July 2013 was 17.09 degs C, not surprisingly given the above, the highest of any month at this location.*  Second highest is now August 2012 [16.07], and July 2006 becomes third [15.58].


Temperature: [Maximum]:
The coolest day of the month was the 11th, where the temperature did not rise above 19.3 degs C, which infact was recorded the previous evening at 2200.  This is not a record however, as in July 2006 the lowest maximum was 20.5 degs C, and in July 2010 it was 19.8.  19.3 degs C is, however, the third warmest 'coolest day' of a month, tying with August 2005.
The highest maximum of July 2013 was 28.5 degs C on the 14th, the second hottest day ever at this location*, with 28.9 being the highest on 19th July 2006.

The hottest day of the month was only three days after the coolest, and from the 12th to the 13th the maximum temperature rose by 7.4 degs C, from 20.2 on the 12th, to 27.6 on the 13th. This 'unusual' heat for West Cornwall was due to the high pressure area moving to a position whereby the airflow arrived in this area from the north-east, the only one of the main eight compass points where there is a distance of over 30 miles of land, rather than water, upwind.
The average daytime temperature for July 2013 was 23.45 degs C, the second warmest month ever at this location*, with July 2006 in first place with 24.68 degs C.

The temperature exceeded 20 degs C on 29 days in July 2013, with the 2nd and 11th the only two days missing out. In July 2010 20 degs C was exceeded 30 times, and in July 2006 it was exceeded on all 31 days.
Perhaps the most disappointing statistic for July 2013 is that the temperature only exceeded 25 degs C on 4 days [7th, 13th, 14th and 18th], compared to 8 times in July 2005, and 10 times in July 2006.
This was due, in part, to the high pressure area not remaining in the optimum position described above for more than a few days, plus the fact that the anticyclone moved away completely with over a week of the month still to go.
Positively however, it was sunny, or mainly sunny, every day from the 5th to the 20th, excluding the mornings of the 11th and 12th.

Rainfall:
36.2 mm of rain fell during the month, making it the driest of any month since March 2012, and the driest July since at least 2007.  [Unfortunately rainfall records were not kept here in July 2006].
This figure compares with 81.7 mm of rain in June 2013, and 104.8 mm in July 2012.
The wettest day itself was the 24th, with 14.9 mm of rain.

There were 20 completely dry days in July 2013, the most of any of the last 6 Julys, and it was completely dry from the 5th to the 22nd.  There were also 23 days with no measurable rain.
Cumulatively in 2013 there has now been 574.1 mm of rain up to the end of July, compared with 595.7 mm for the same period in 2012.  This is the first end of month figure where the total of rain so far has been lower for 2013 than 2012.  At the end of March 2013, 2013 had seen 180 mm more than 2012!

No thunder during the month.

*Since at least October 2003.