Once again the maximum on Monday of 19.0C was below average (-3.9C) whilst the overnight minimum of 12.8C was above the average (+0.9C).
The month finished with another 0.9mm of rainfall and the UV level in the ‘Moderate’ category.
Tuesday began bright and sunny until after 13.00 when encroaching cloud began to obscure the sun.
July 2023 review
A conveyer belt of depressions plagued much of the month.
Although the month began dry, as was much of June, very useful rainfall for the gardens fell on the 4th, over six hours during the evening with steady, moderate rain that amounted to 18.4mm. This was thanks to a small depression that developed over southern England and ran along the south coast.
The dry day on the 7th produced the warmest day of the month with the thermometer peaking at 27.9C.
We then entered a variable run of weather in the second week with low pressure dominating that brought several days when the maximum temperature was below average.
A deep depression approached the UK on the 13th that brought twelve hours of continuous rainfall and strong winds with a maximum gust of 25mph. The daily rainfall total was 27.9mm making it the wettest day since 19th December 2022 ((29.8mm). The deep low gave a barometric pressure reading of 998.6mb at 08.00 on the 15th, the lowest pressure since 12th April. The diurnal range of temperature was low for this time of year, just 3.9C between the maximum of 17.9C and the minimum of 14.C.
It got even windier on the 15th as the deep depression eased away over Scotland with the strong winds on its southern flank peaking locally at 35mph. This was not a record for July as a peak gust of 41mph was recorded on 7th July 2004. The strongest gust I have ever recorded was 56mph on 18th February 2022.
Sunday the 16th was plagued with frequent rainfall from a line of successive showers that crossed the area with minimal sunshine between, producing another 5.2mm.
A few drier days followed before another very wet day arrived with rain and drizzle for 13 hours on the 22nd amounting to 21.7mm.
The wind then very briefly veered into the northwest, a cooler direction, that saw the thermometer drop to 5.4C in the early hours of the 26th. This was due to a very brief ridge of higher pressure. The low was a significantly 6.5C below the 39-year average and the coolest night since 17th May 2023.
A mixture of sunshine and showers completed the month.
It was unusually cool for July by day but not by night. The average maximum temperature was 2.0C below the 39-year average due to the lack of sunshine. However, the average minimum was 0.1C above the average, principally due to the numerous nights with cloud cover under the moist, warm Atlantic air.
The mean temperature of 16.2C was 0.9C below average making it the coolest July since 2015, which had an identical mean. For comparison, the hottest July day in 2023 gave us a maximum of 27.9C (7th) against a peak of 36.7C (19th) in July 2022.
There were only 3 days in the month when the maximum rose above the average temperature, however, there were 16 nights when the thermometer was above average.
July was also memorable for the quantity of rain that fell, which amounted to 115.8mm. This was 199% of the 39-year average or +57.6mm. This made it the second wettest July I have recorded since my station was set up in 1984, the record being held by July 2007 when 127.2mm of precipitation fell. The driest July was in 1988 when just 14.69mm of rain was recorded.
The rainfall in July has shown an upward trend since my records began in 1984 and risen from an average of 52mm to 60mm over recent years.
There were just 14 totally dry days against the average of 18. It is important to pick out the three very wet days when the precipitation continued for twelve or more hours and ran well into double figures, namely 18.4mm on the 4th, 27.9mm on the 14th and 21.7mm on the 22nd.
The mainly cloudy month meant that there was limited sunshine and the average UV level of 8.9 was well below the long-term average of 9.4 for July. The global sunshine measured at 100w/sw.m, was just 93% of the long-term average.