Saturday 6th September
The variable sunshine on Friday, especially in the morning gave us the warmest day for a week with the thermometer rising to 21.3C at 16.00 being 2.4C above average. It was also the first dry day this month with the UV level rated at it speak at the top end of ‘Moderate”.

Under clear skies the temperature dropped away to 9.6C by 03.43 early Saturday being 0.9C above average.

Looking across the countryside after dawn on Saturday revealed radiation fog had formed in both the River Og valley and the River Kennet valley. The ground is still damp from recent rain thus the air is more humid, a reading of 96% was logged at 08.00. As the temperature drops overnight the moisture in the air condenses, especially near a water cause such as a river, forming fog. In fact, my station is perhaps 500m from the river and I noted at 06.30 that the temperature was 10.3C whilst the Dew Point was 9.6C, the latter being the temperature at which the air cannot hold any further moisture and forms fog or mist. By 07.30 the fog had dispersed in the River Og valley while that in the Kennet took another half hour to disappear.

The high pressure has moved across to the Continent, as forecast yesterday, as a result the air will arrive today on a southeasterly breeze bringing warm air from the near Continent.