Hot sun and Very High UV return on Saturday

Under the influence of the anticyclone, centred over the south western approaches, Saturday was a superb day. We enjoyed 11.5 hours of strong sunshine with the UV level rated at ‘Very High’ from 11.30 to 14.30.

It was the fourth dry this month. The rate of evaporation is increasing again with the equivalent of 4mm of rainfall lost to the atmosphere on Saturday. The rainfall total of 15.6mm has been overtaken by the total evaporation in July of 28mm.

Even though we had much sunshine the air flow from the north west, brought on light winds gusting to only 14mph, pegged back the peak temperatures to 20.7C being 2.1C below average but 2.4C up on the Friday peak.

Overnight under the clear skies, the thermometer fell away to a minimum of 5.9C, which was 6C below the 36-year average but almost exactly the same as the previous night’s minimum.

Sunday arrived with sunshine after dawn but dimmed occasionally through light thin cloud and more aircraft condensation trails that have been evidentin previous months.

Cool by day and night thanks to wind change

What a difference a change in the wind direction makes as the high pressure exerted itself. The wind, from the previous night, had veered into the nor nor west, a much cooler direction. As a result daytime temperatures were depressed with a maximum of 18.3C, being 4.5C below average. It was a totally dry day, welcome after the previous damp days.

Overnight under clear skies, the thermometer fell rapidly to a minimum of 5.8C at 05.31 on Saturday, which was 6.1C below the 36-year average. That was 6C below the previous night’s minimum.

Saturday dawned with glorious sunshine in a clear blue sky that boosted the temperature to 13.9C at 08.00. The barometric pressure has been rising steadily with a current reading of 1026.5mb, being the highest since the end of May.

More gloom and drizzle but change late in day on Thursday

The low cloud bringing mostly bouts of light drizzle continued on Thursday but totalling only 1.1mm. The wind continued from the south west for much of the day bringing the moist Atlantic air but just before 18.00 the barometric pressure began to rise with a major change in wind direction from southwest to north. We have now had four consecutive days with almost identical maxima namely 19.6C, 19.5C, 19.6C, and 19.7C on Thursday, very unusual and all below the average of 22.8C.

Overnight the clear air from the north meant a cooler night with the thermometer sinking to 11.8C, just average. The wind was very light with a maximum gust of just 15mph, the calmest day all month.

After so many days with cloudy, damp starts it was a treat to see the sun shining again lifting the temperature to 13.7C at 08.00

Little variation in daytime temperatures this week

As we are still under the influence of the moist Atlantic air it is not surprising to find that the maximum on Wednesday was again below average with a cool westerly breeze with a peak 19.6C. The maxima for the past three days were almost identical being 19.6C, 19.5C, and 19.6C respectively. Only 2.4 hours of sunshine triggered the recorded.

There were intermittent showers amounting to 3.4mm. This brought the total for July to 14.5mm when the average is 59.7mm.

The past night saw a minimum of 14.4C, similar to the previous night when 14.0C was recorded.

Thursday arrived with a similar overcast sky to Wednesday but currently dry although the humidity is high with a reading of 96% at 08.00.

Dry day, wet night

After a bright morning the cloud built up ahead of the next weather front advancing from the Atlantic. As a result of afternoon cloud and reduced sunshine, 6.5 hours, the maximum temperature was again below average (-3.3C) with a peak of 19.5C.

The first rain shower arrived just after 23.30 with more persistent rain after 03.30 that amounted to 3.9mm. The thick cloud provided a duvet overnight so little warmth escaped into the atmosphere thus providing a mild night with a minimum of 14.0C being 2.1C above average.

Wednesday dawned with thick, low cloud and light rain continuing as the depression out to the west lowers the barometric pressure to 1013.8mb at 08.00.