Author: Eric Gilbert

The mist and murk from the depressingly low, thick cloud was even more persistent and dense on Saturday than during Friday producing another sunless day. The solar energy level was at its lowest since 27th February.

The air continued to be humid and with the lower temperatures than last week produced the condensation that formed the thick cloud and bouts of drizzle along with a couple of very light showers just after midnight amounting to 0.7mm.

Saturday was an unusual day as the temperature continued to fall away until 09.45 when it slowly began to rise reaching a maximum of 17.8C at 23.39, not during daylight hours. The minimum of 17.1C occurred at 03.39 in the early hours of Sunday before the thermometer began to rise again reaching 17.9C at 08.00 Sunday.

In my report on Saturday I referred to the diurnal temperature being the temperature range between day and night. The variation over the past twenty four hours was minimal at 1.6C.

Sunday saw the thick cloud again draping the Marlborough Downs with visibly down to 300m but shortly after dawn it slowly began to lift and after 07.30 a few brief bright intervals occurred before the cloud filled in again.

Friday was the first day since 4th July when no sunshine was recorded due to the continuous thick, low cloud. Professionals on the tv seem to frequently refer to this as mist and murk, which sums it up well. During the day and past night there were frequent very light showers and light rain or drizzle that amounted to just 3.8mm.

Unusually the peak temperature was only reached in the early evening at 19.22 with 18.8C, the first below average maximum since 3rd August. The other interesting point to note is that the diurnal temperature, that is the difference between day and night, was just 3.3C with a minimum of 15.5C being 4C above average.

Not surprisingly the solar energy was the lowest since 10th March when August is supposed to be a summer month. The UV level never rose above ‘Low”.

Saturday arrived with no change from the low, thick cloud draping the Marlborough Downs and Savernake Forest, visibility varying between 1,000m and 2,000m.

It is interesting to note the falling away in temperature each morning at 08.00 from the peak on Wednesday with 22.1C, 19.6C, 16.3C and today 15.6C.

On Thursday a cloudy, moist morning meant the sun did not make an appearance until after midday and during the afternoon the sky was hazy so the maximum of 25.5C was well down on the Thursday peak of 34.1C but 4.5C above the average. Light showers occurred late afternoon and overnight amounting to 1.8mm.

The rainfall for the past twenty-four hours amounted to 4.6mm that brought the monthly total to just 5.8mm however the equivalent rainfall of 44mm has been lost through evaporation.

Friday arrived with overcast skies under calm conditions and a brief intense shower at 07.20. The lower temperatures and modest rainfall has lowered the soil temperature at a depth of 5cm from a peak 24.2C to 20.5C on Friday at 08.00.

Once again on Wednesday the mass of humid and hot air pushed the thermometer very high to reach a maxim of 34.1C, exactly the same as on Tuesday, but a little earlier in the afternoon at 15.55. Thereafter cloud began to build in the east as an approaching storm threatened rain. However, as on several previous occasions, it veered around this area without producing any rain, but reformed to the west shortly afterwards. At 17.15 several claps of thunder were heard and the wind gusted to 24mph, the strongest since 27th July.

The heat was slow to dissipate overnight due to the cloud cover so that we almost experienced a tropical night (minimum 20C) but not quite, as the thermometer dropped to a low of 19.4C at 07.05 Thursday. This was the second warmest night my station has recorded since set up in 1984, the record being set on 20th July 2016 when a minimum of 20.2C was recorded, a true Tropical Night.

Thursday arrived with total cloud cover and a few spots of rain at 07.20, but not measurable, which immediately evaporated. The air was almost still at 08.00, just the occasional movement, variable in direction as yesterday but principally from the north east. The charts show these conditions are due to a long ‘trough’ of low-pressure, stretching west to east, across central Southern England rather than the centre of a depression, which is over France.

Update on Thursday at 18.30: cloud during morning and late afternoon limited heat to a maximum of 25.5C at 14.43. No measurable rain, just a few spots

Tuesday brought 9.8 hours of strong sunshine with the UV level at the top end of’High’. The thermometer climbed steadily throughout the day to reach a maximum of 34.1C at 16.27. This was the hottest day since the record maximum of 34.9C was recorded on 19th July 2006. The station opened in 1984.

The wind was very light throughout the day with a maxim movement of just 11mph. The wind direction was variable initially coming from the north east but veering into the east and briefly into the south late afternoon. During the evening a dramatic storm cloud was observed to the north east as a major storm developed over Oxford.

There was minimal loss of heat from the ground through radiation during the last night so not surprisingly it was very warm. The minimum of 18.2C at 06.27 on Wednesday morning was 6.6C above the 36-year average and was the hottest night since the same temperature was recorded on 24th July 2019. So not a ‘Tropical Night’ as has been mentioned in the weather forecasts for some areas of the country but a tropical night set the record for this station on 20th July 2016 when a minimum of 20.4C was recorded.

Wednesday saw strong sunshine shortly after dawn as the sun cleared cloud on the eastern horizon. The heat continues to be absorbed by the very dry ground with the temperature of the soil at a depth of 5cm at 08.00 was 24.3C.

Update on Wednesday at 19.30: maximum exactly as on Tuesday with a peak of 34.1C that occurred a little later in the day at 17.15 before cloud built up from an approaching storm but no rainfall as yet again storm eased around the area.