Tuesday 23rd December
The sun did eventually break through on Monday that lifted the temperature to a peak of 10.4C at 12.02 before the cloud rolled back in again on a modest easterly breeze. The maximum was 2.9C above average. The temperature began to very slowly edge downwards after 21.00 on Monday evening, this resulted in a low of 6.6C at 08.00, and is continuing to fall.
Tuesday arrived grey and dark under thick, low cloud that has been dragged in from the North Sea thanks to a brisk breeze, today from the northeast. The visibility is restricted as the cloud base is very low draping misty conditions across the top of Savernake Forest and the Marlborough Downs.The northeasterly breeze is already producing a wid chill so that at 08.21, when the thermometer had fallen further to 6.4C, it felt more like 5.9C outside. The air today is much drier than that recently brought from the Atlantic Ocean, with a humidity of 92.6% at 08.00.
The recent low-pressure is now over the Mediterranean thus allowing the high pressure over Scandinavia to push further across the country. This anticyclone will continue to build across the UK for the next two days. There will be an increasing pressure gradient between the two systems that will result in the wind rising, especially on Christmas Eve. The combination of a strong, cold northeasterly will mean that wind chill will be significant, that outside it will feel much colder than that indicated on a thermometer. The blast of very cold air will mean both maxima and minima temperatures for the next few days will be below average, in contrast to most of December. Every day this month has seen the maximum rise above average, often by many degrees.