Saturday 3rd January
There was snow to the north and east of our area, however, as the temperature fell away after dawn the wet surfaces, from the brief rainfall earlier, froze and turned into black ice in places. The limited weak sunshine raised the temperature to a peak of 3.4C being 3.7C below average. The thermometer dropped to a minimum of -1.3C just before midnight then rose and fell like a roller coaster in the early hours, rising to 0.7C at 05.56 before falling away again to -1.3C at 08.00. By 08.30 the thermometer had begun to edge upwards reading -0.9C.
First light on Saturday revealed clear skies, which will allow welcome sunshine for much of the day, however, the light breeze from the northwest is still dragging down the Arctic air so it won’t be very warm with the maximum well below average before the another frost sets in tonight.
The cold conditions will be with us to at least Tuesday as the wind streams down between the depression to the east and anticyclone to the west. There is the possibility of something less cold from Wednesday onwards as the wind will back a few degrees to come from the west. However, the temperatures by day and night will continue to be below average as there is no warmth in the ground to compensate for the cold air. The soil temperature at a depth of 5cm read -0.6C as the cold by day and night seeps into the ground.
The evenings have lengthened by 12 minutes since the shortest day whilst the sunrise has been static at 08.12 since the 26th and won’t change until the 6th. The reason mornings do not lengthen at the same rate as evenings at this time of year is due to a combination of the earth’s axial tilt and its elliptical orbit around the Sun, a phenomenon astronomers call the ‘equation of time’. More detail tomorrow.