Author: Eric Gilbert

September proved to be a month of contrasts. The first few days were very warm and dry with a maximum of 27.1C on the 4th, the fourth highest I have recorded. However, as the month progressed temperatures fell away many degrees below the average with a low maximum of only 12.9C on the 17th. During the latter part of the month the Scandinavian high pressure brought a welcome lift in temperatures, sunshine and minimal rainfall. The mean temperature was very close to the long-term average being just 0.02C above.
A very dry start to the month was broken in the middle by substantial totals of 19.2mm and 15.4mm on the 13th and 17th respectively. This figure contrasts with the extremes of 11.1mm in 2009 and previously in 2006 of 131.9mm.
There was a disappointing amount of sunshine, the total being the lowest for five years, 96% compared to the last few years. Not surprisingly, the figure for solar power was well down at 87% compared to the average for recent years.

Friday 13th September was the wettest day for six months. After nearly eight hours of rainfall the total for the 24 hour period was 25.1mm. This total was just exceeded by a fall of 25.2mm on 15th March 2013.

August 2013
August started with a very hot day that peaked at 30.2C, the fifth hottest day that I have recorded. The record of 35.2C was set on 3rd August 1990. There were only four days in the month that did not exceed 20C. The mean temperature was 0.5C above the long-term average, almost identical to 2012 and the warmest since 2004.
It was a relatively dry month with a total of only 43.6mm that is 67% of the long-term average and the driest since 2005. This is in contrast to the massive total of 108.8mm last year. The wettest August was in 1992 with 139.5mm and the driest occurred in 1995 with a mere 5.3mm. Evapotranspiration amounted to the equivalent of 76.9mm of moisture, which is 33.3mm greater than the rainfall total.
There were 308 hours of bright sunshine, which is 20% above the average for recent years. Solar power was 5% above the average for the last few years.

Summer 2013
This was the warmest summer season, with a mean of 16.6C, since the record set in 2006 (17.9C) and was 0.6C above the long-term average.
Summer 2013 was also noted for the relatively low rainfall total of 141.4mm being 77% of the long-term average, It was the driest since 2003. The record for the highest rainfall of 328mm was set last year and the driest in 1995 when only 53mm of rainfall was noted for the whole summer.

July was a month that brought summer weather at last as it was 1.8C above the long-term average; the maximum was +2.9C and the minimum +0.6C. It was the third warmest July I have recorded and the warmest (18.6C) since 2006 (19.97C) and 1989 (18.91C). A maximum of 31.7C on the 22nd was the highest since 2006 when the record for July of 35.9C, was set on the 19th. There were 19 consecutive days without rain, the longest dry spell since April 2007. During this period the evaporation from plants and the ground amounted to over 85mm of water vapour returned to the atmosphere, many days each in excess of 5mm. The total figure for evapotranspiration was 118.7mm, which meant a deficit over precipitation of almost 55mm even though rainfall was above average.
The rainfall total of 63.8mm was 106% of the long-term average and principally due to heavy rain on three days of 18.2mm,17.6mm and 17.1mm on the 27th, 29th and 22nd respectively. July rainfall, although slightly above average, was so much drier than the recent years of 2009 (113mm) and 2007 (127mm). As the anticyclone drifted away during the last week or so, humidity rose as very warm southerly winds brought thunderstorms on the 22nd, 23rd and 29th.
As a result of the persistent anticyclone, solar energy was 125% of the average for recent years and there were many days with high levels of UV that on the 31st produced an extreme value for late July of 10.0 when the average was 7.7.
Early morning fog was noted on two days during the month along with two very misty mornings.

June was the sixth successive month with a mean temperature below the long-term average at -0.7C. There were several very cool nights with a low of 3.5C on the 3rd, being the coldest, but a few warm days. A maximum of 25.2C on the 19th was the lowest maximum since 2002. Looking back over the records I note that June 2013 was the coldest June since 1994.
It was the driest June since 2006 with a total rainfall of just 34.0mm, being 59% of the long-term average.
Sunshine total for the month was close to the average although the solar energy total was the highest since 2006.
There were three notable days when UV levels were extremely high during June, with a maximum of 10.4 meds on the 28th.