Heatwave well under way!

The thermometer soared to 29.5C on Monday being the warmest day for a week and 4.8C above the 38-year average. The light southerly breeze brought the first evidence of a ‘Spanish Plume’ with hot air from the Spain and Portugal. Overnight was again cool, thankfully, with a minimum of 10.9C, which was 1.0C below the average and 0.2C lower than the previous night.

Tuesday bought strong sunshine shortly after dawn that saw the thermometer rise very quickly to reach 22.0C at 08.00. This was the warmest start to a day since 20th July 2021 (22.9C).

Under the relentless sunshine, hot air and minimal rainfall, the ground is very dry thus the very low humidity reading at 08.00 of just 59%, the lowest humidity since July 15th 2013 (54%).

The barometric pressure has dropped 5.4mb since Monday as the high pressure relocates to eastern Europe and the low pressure system over Portugal begins to make itself felt carrying the hot air from far south.

Update at 10.00: current temperature of 29.9C.
11.00: temperature of 31.8C
12.00: temperature of 32.6C
13.00: temperature of 34.2C
14.00: temperature of 34.2C
15.00: temperature of 34.6C
16.00: temperature of 34.3C
16.30: temperature of 35.2C
16.47: peak temperature of 35.8C – surpasses previous record of 34.8C set on 19th July 2006.

N.B. My accurate weather instruments are situated up the garden some distance from hard standing and buildings.Importantly, they are well ventilated and completely shielded from sunshine and solar energy. The site is on the outskirts of Marlborough so the peak temperature in town could well be a degree or more above that recorded on my instruments. The station was established in 1984.