Monday 22nd June
The variable high, thin, fair weather cloud on Sunday muted the sunshine a little, however, the heat continued to build, resulting in a maximum of 28.7C at 18.21, which was a significant 10.0C above my long-term average. The past night has been very warm with the thermometer not sinking below 17.0C at 05.15 early Monday, being 6.8C above average. The peak UV light was, not surprisingly, in the very high category.
I mentioned yesterday that there were calm conditions overnight and well into the morning, which was correct. However, I discovered mid morning, when there was a little stirring of the atmosphere, that gossamer threads had floated across the area and had trapped the anemometer cups thus stopping the assembly moving. These threads were quite strong that needed a modest push of the anemometer to break them and get the cups rotating again.
Monday began with strong sunshine after it had risen above some thin cloud and aircraft contrails. The barometric pressure has continued to rise, a reading of 1026.4mb was logged at 08.00, as the centre of the anticyclone is now in the North Sea, just off the east coast of the UK. This position will mean a feed of air from the east or east-southeast, driving hot air towards us from the very hot Continent.
The peak of 28.7C exceeded the heatwave threshold for Wiltshire of 27C. Although it is not an official heatwave yet until three successive days peak at or above 27C, this is now certain to occur as we will likely have at least five days that will produce heatwave conditions.
The Met Office heatwave threshold has been updated ahead of summer 2022. The initial heatwave thresholds were calculated based on the 1981-2010 climatology of daily maximum temperature at the mid-point of the meteorological summer (15 July). The revised thresholds will use the 1991-2020 averaging period introduced in January 2022. The geographical differences reflect the differences in climate across the UK.
With summer upon us I thought it appropriate over the next week or so to take a stroll through Compton Acres, which is a large privately owned garden in Poole, Dorset, which was founded in 1920 by Thomas Simpson an entrepreneur, who had become wealthy through the manufacture of margarine.