Clear and cold overnight.
This Evening and Tonight:
Rain in Cornwall at first will clear to leave the rest of the night dry across southwest England. Clearing skies and easing winds mean that temperatures will fall quickly, bringing a cold start to Friday. Minimum Temperature -2C.
A bright but cold start, then much of Friday will be dry with occasional sunny spells, mainly in the east. However it will cloud over later, perhaps with some rain. Maximum Temperature 7C.
Outlook for Saturday to Monday:
Winds strengthen Saturday, as rain spreads east. Turning less cold Sunday with sunny spells and heavy showers later. Dry on Monday but increasingly windy in the afternoon.
Day 6 to 15
Tuesday will see some unsettled and windy weather with coastal gales, cloud, and outbreaks of rain and drizzle moving eastwards across the UK. The rain and drizzle will be followed by sunny spells and scattered, blustery showers. Showers will fall as snow over northern higher ground. As we head through the remainder of the week and into the Christmas week it will probably stay unsettled, with further spells of wind and rain, these interspersed by some brighter and showery weather. Temperatures on the whole look likely to be a little milder than average. However, in the period after Christmas Day there is an increased likelihood that milder spells will become short-lived and a colder and more showery northerly or northwesterly regime could become established across the UK.
Day 16 to 30
The most likely scenario for the end of December is for periodically unsettled Atlantic weather to move across the UK from the west. However, there is an increased likelihood that the milder, Atlantic weather will become short-lived and a colder and more showery northerly or northwesterly regime will become established across the UK. Through the first half of January, there is an increasing likelihood of a return to colder than average conditions with an increase in the likelihood of overnight frost and fog, as well as some snow.
Met Office : SW : 2018-12-13T15:26:17