The breeze on Wednesday originated in the far north and was brought down on a light northerly drift, called an Arctic Maritime Airmass, having originated in the Arctic and travelled over a large area of sea.
As a result of the very cold air the thermometer struggled to get to 4.1C which was 4.0C below the December average. There was very welcome sunshine in the morning but cloud drifted across after midday so that by 13.10 the sun had all but disappeared. The breeze was light with a maximum gust of 10mph thus windchill was minimal.
By 13.30 the thermometer had already begun to fall and continued until it reached a minimum of -6.1C at 04.52 on Thursday morning. The low was a significant 8.6C below the 38-year average and the coldest night since 21st/22nd January 2022 (-6.4C). The record for the coldest December was set on December 20th 1999 when the thermometer dropped to 13.5C.
The Arctic air is due to a large area of low-pressure over Scandinavia, which as it circulates anticlockwise produces a northerly wind direction. The nearness of the depression has given a barometric pressure reading of 1014.0mb, down 10mb since this time yesterday