Category: Commentary

The anticyclone continued to bring hot, sunny weather on Monday with 11.6 hours of sunshine and very High UV levels. The thermometer did not quite reach as high as on Sunday with a peak of 31.4C being 8.7C above the average.

The Meteorological Office yesterday broadcast their first Extreme Heat warning that lasts until Thursday evening. This is not only due to the high daytime temperatures but also the very warm nights. The past night saw the thermometer not fall below 14.2C, which was 2.3C above the average.

The ground temperature at a depth of 5cm read 24.0C at 08.00 as limited warmth radiates into the atmosphere overnight.

Strong sunshine welcomed the arrival of Tuesday that pushed the thermometer to 22.9C at 08.00.

Another feature of recent days, under the influence of the high pressure, are the very calm days with little movement of air. At head height the last two days have seen a maximum air movement of just 8mph and 9mph with frequent periods of total calm.

Update at 19.00: thermometer eased upwards again with a maximum of 31.6C (89F) at 14.29.

Although the sunshine hours of 11.8 were slightly down on Saturday the residual heat from a warm night saw the thermometer on Sunday rise to 31.7C, which was 9C above the 37-year average and the hottest day since 12th August 2020 (34.1C). It was also equal to the hottest part of the country. The UV level again rose to Very High. My station is on the northern edge of Marlborough and sited up the garden away from concrete and buildings.

The breeze was very light on Sunday with a maximum movement, cannot call it a gust, of just 8mph. For long periods the anemometer was becalmed but when it did move the air movement came from many compass directions so described as variable.

The temperature overnight was very high with a minimum of 14.0C being 2.2C above average.

Monday again saw strong sunshine after dawn that propelled the temperature to 23.1C at 0800 so at that time was already above the average maximum for July of 22.7C. After five consecutive dry days and intense sunshine the humidity level at 0800 read 74%, the lowest since early June when we had similar hot weather.

Update at 10.00: temperature of 28.3C and rising steadily

Update at 20.00: peak temperature of 31.4C at 15.39

During the 12 hours of strong sunshine on Saturday, the sunniest day since 23rd June, the thermometer rose to 28.1C. This high was 5.4C above the 37-year average and the hottest day since 12th August 2020 (34.1C). Not surprisingly the UV level rose to Very High again for three hours around midday.

As the centre of the high pressure moved very little in the past twenty-four hours, centred just off the Irish west coast, the light breeze with a peak gust of 12mph, continued to come from the northeast.

We experienced a slightly cooler night than the previous night, but still very warm, with a minimum of 12.5C, which was 0.7C above the average.

Sunday saw the welcome sight of strong sunshine as the sun rose above the horizon that lifted the temperature to 21.8C at 08.00, the warmest start to a day at that time since 12th August 2020. The barometric pressure has varied little over the past twenty-four hours with a reading of 1026.9mb at 08.00.

The soil temperature at a depth of 5cm read 22.3C at 08.00 as there is minimal loss to the atmosphere due to high day and night time temperatures.

We have now enjoyed four consecutive dry days with the daily evaporation now the equivalent of over 4mm of rainfall.

Update at 18.40: peak temperature of 31.7C at 16.22. Hottest day since 12th August 2020.

The Azores anticyclone made itself felt on Friday with 11.5 hours of sunshine, the sunniest day since 23rd June (12.2 hours) during which the UV rose to 8.2 for a couple of hours around midday, which was Very High. It was the third consecutive dry day. The thermometer rose to a maximum of 26.9C late in the afternoon at 16.50 being 4.2C above average and the warmest day since 13th June (27.9C). The peak was 4C up on the Thursday high.

There was more residual warmth overnight that meant a warm night with a minimum of 13.3C, which was 1.4C above the average. The low was 4.3C above the very cool Thursday minimum.

Saturday saw sunshine as soon as the sun rose above the horizon that lifted the temperature to 20.9C by 08.00, the warmest morning since 24th June.

The centre of the anticyclone is just off the west coast of Ireland and has been building further with a pressure of 1029.6mb at 08.00, the highest pressure since 13th June when we had the last hot, dry spell.

Although there was more cloud on Thursday the thermometer climbed just above average to reach 22.9C (+0.2C) in the 9.9 hours of sunshine with the UV level again reaching Very High. It was another dry day.

Overnight was chilly. The thermometer dropped away to 8.9C being 2.9C below average that produced radiation fog on Friday morning that just after dawn limited visibility to 200m.

Friday at dawn saw the sun struggling to pierce the thick radiation fog but at 0700 the visibility had improved to 500m and by 0800 to around 2000m.

The centre of the anticyclone is now just off the southwest tip of Ireland with the high pressure ridging over the UK. This is producing a north to northeast breeze that was still light on Thursday with a peak gust of 13mph at ground level and a current reading today of 1027.5mb at 0800. This is the highest barometric pressure since 13th June.