Author: Eric Gilbert

Monday was a much less hot day with the thermometer only reaching 26.8C due to considerable and variable cloud cover. This was the coolest day since the 6th but still 5.7C above the average. Twice a few spots, later;a;y were felt and seen but evaporated immediately.

Two considerable shower areas passed to the west over Swindon and east over Hungerford late afternoon avoiding once again the Marlborough area. However, a very narrow rain band passed over Marlborough at 04.15 producing just 0.3mm. Light rain was observed beginning to fall at 07.25.

Due to the residual heat and overnight cloud it was a warm night with a minimum of 15.1C being 3.4C above the average.

Tuesday arrived with total could cover and very light rain as mentioned above. Due to the complete change in the weather pattern, now a low pressure system close by also light rain, the humidity at 08.00 read 96%, which was the highest at that time for the month.

Update at 19.00: substantial rain from 16.55 to 18.15 amounted to 15.9mm.

The peak on Sunday of 33.2C was just below the high on Saturday (33.5C) but still 12.1C above the 38-year average.

Late afternoon, just after 18.00, the wind direction began to veer from the east, where it had been for four days, into the southeast and just before midnight into the southwest as a depression approached the UK.

We have now endured 8 days under heatwave conditions, for Wiltshire the heatwave threshold is three consecutive days with maxima equal to or above 27C.

The loss of equivalent rainfall due to evaporation from the ground and plant life continued to be in excess of 4mm. The statistics are, rainfall nil and evaporation 55mm.

It has been a very warm night with the thermometer not sinking below 14,5C. That low was 2.8C above the average and the warmest night since the 3rd (18.1C)

The start to Monday was so different to the last week or so. There was no blazing sunshine after dawn due to thick cloud on the eastern horizon. However, just after 07.30 there were glimpses of sunshine that an hour later were very muted due to increasing cloud.

The soil temperature at a depth if 5cm read 23.1c at 08.00, the highest this month due to the heat on Sunday and a very warm night.

The wind is due to veer further as the morning progresses to come from the west northwest or northwest as the depression advances. The barometric pressure of 1002.2mb is the lowest this month.

During the late afternoon on Saturday the thermometer soared to 33.5C after hovering around 33.4C for an hour. This maximum was 12.4C above the average and the hottest day since 19th July (36.7C).

The overnight minimum of 11.1C was slightly down on the previous night and 0.6C below the average.

Sunday brought the first obvious changes to our weather after numerous days with clear but skies there was thin high cloud that limited the strength of the sun initially. However, by 08.00 the thermometer had recovered to 19.7C.

The humidity at 08.00 was exceptionally low with a reading of just 64%.

The anticyclone is slowly retreating with the barometric pressure at 08.00 reading 1008.7mb, which was the lowest pressure for the entire month and a fall of 22mb since the peak on the 6th (1030.4mb).

Further evidence of a change in our weather is imminent with a forecast change in wind direction later this afternoon as the wind changes for the persistent easterly to southerly.

Another cloudless day on Friday that brought the hottest day since 19th July with a maximum of 33.2C being 12.1C above the 38-year average. My station is sighted up the garden away from buildings and hardstanding as far as I can get also we are on the edge of the town, therefore temperatures in the town centre will be above this this peak. The light breeze, predominantly from the west, continued. The UV level of 5.8 was the lowest for a week but still in the High category.

The past night was the first minimum above average (+0.3C) since the 3rd with a low of 12.0C at 05.52.

Saturday began as previous day this past week with strong sunshine after dawn that lifted the thermometer to 19.9C at 08.00. The heatwave has new lasted seven days as we live under a Heat Dome due to the high pressure trapping the heat beneath it. The centre of the anticyclone is slowly declining with a reading of 1015.2mb at 08.00, a drop of 14mb since its peak.

Update at 16.50: maximum of 33.4C at 16.24, which was up 0.2C on the Friday peak and 12.3C above the 38-year average.

The thermometer soared to 32.5C last afternoon on Thursday being 11.4C above the average and the warmest day since 19th July (36.7C).

The UV level of 6.2 continues at the High rating.

The minima over the past few nights have continued to rise as the very dry ground absorbs more and more warmth. The past five nights have brought 9.2C, 9.5C, 9.4C, 10.8C and 10.6C respectively. All these minima were below the 38-year average of 11.72C so at least a cooler start to each day.

Friday began as previous days with strong sunshine after dawn that produced a temperature of 20.8C at 08.00 making it the warmest start to a day at that time since 19th July 2022 (24.5C).

The humidity at 08.00 was, not surprisingly exceptionally low, with a reading of just 64%.

The ground temperature at a depth of 5cm read 22.4C at 08.00, the highest temperature since 20th July 2022 (24.3C).

Update at 17.00: maximum of 33.2C at 16.30.