Highest temperature, evaporation and solar this month on Wednesday

As the anticyclone edged closer the temperature on Wednesday rose even higher to reach a maximum of 26.2C, the highest since 8th September 2021 and 6.0C above the 38-year average.

It was another dry day with just 12.0mm of rainfall this month. The heat and many hours of strong sunshine recently have increased the daily loss of equivalent rainfall through evaporation to 4.68mm and 4.76mm during the past two days. The equivalent loss of rainfall this month now totals 46mm, almost twice the actual rainfall.

The thermometer fell way to 6.8C overnight but recovered to 17.8C at 08.00.

Heatwave Threshold.
The thermometer has to reach at least 27.0C for three consecutive days to be classed as a heatwave for Wiltshire. The possibility is that both Thursday and Friday could see that temperature reached but Saturday is forecast to be cooler.

The official Met Office weather stations are situated on large grassed areas well away from any hard surfaces and buildings as these hold the heat. My weather station is on the northern edge of Marlborough and sited well up the garden, therefore a thermometer in the centre of town, midst buildings and solid surfaces, will register an even higher temperature than my station.

Tomorrow I will include up to date data on recent heatwaves and the trends in frequency and temperature.

Update at 19.20: maximum of 28.5C at 16.14. Highest daily maximum since 7th September 2021