The averaging period used for the following assessment was 1961-1990.
A very wet month across England and Wales and south-eastern parts of Scotland. It was much drier than average across north-west Scotland. Most eastern areas experienced a very dull month, but in contrast western areas were sunnier than average.
Dyce and Leuchars only experienced around a third of their average sunshine for the month. Aviemore had around 16% of their monthly rainfall, whilst Dyce and Leuchars received around 152% of their normal rainfall.
England and Wales diary of highlights
Changeable with some cold and dry periods then unsettled wet and very mild.
1st to 4th Changeable weather with rain and showers especially in west and north-west as areas of low pressure and weather fronts moved south-east. It was mainly mild, with some thunder reported on the 4th. A gust of 61 kn was recorded at Aberdaron (Lleyn Peninsula) on the 1st.
5th to 11th High pressure over Scandinavia brought cold easterly winds, however it was mostly dry. There were sunny periods at times and some patchy rain or drizzle mainly in the south. There was some sleet or snow in the north on the 7th, also over Dartmoor and north-east England on the 8th. A depression over Biscay on the 10th strengthened the easterly winds, bringing a little snow to high ground in the West Country.
12th to 16th Dry in most places at first. A low moving slowly north-north-east from Biscay reached south-east England by the 15th and brought outbreaks of rain with sleet and snow (mainly over high ground). It was rather cold and very wet on the 14th and 15th, patchy hill and coastal fog affected a number of areas.
17th to 19th An anticyclone centred over the Borders migrated east-south-east to the continent bringing cold easterly winds and some overnight frost especially in the north. There were sunny spells later, with some fog in northern areas. Rain reached Cornwall and Devon later on 19th.
20th to 23rd Redesdale in Northumberland fell to -6.6 °C early on the 20th, thereafter more unsettled weather prevailed as Atlantic lows swept very mild moist air across the region. Many places had a very wet 36 hours from late 20th to early 22nd causing local flooding. Llanbedr in Gwynedd reached 15.4 °C on the 23rd.
24th to 27th Vigorous depressions from the south-west passed close to or over the region, bringing more rain and heavy showers. It stayed mostly very mild, the three-day Christmas period was one of the mildest for at least a decade. Flooding continued to be a problem in many areas.
28th to 31st After a mainly dry start, more very mild but very wet weather spread north-east during the 29th and 30th as a low and its fronts stalled over the region. Prolonged heavy rain accentuated the flooding problems. During the 30th there were isolated reports of thunder, while at Brighton a section of the West Pier fell into the sea. Central London had its wettest December on record (since 1940). Most places began dry and cold on the 31st before further rain spread in from the south-west.
Scotland diary of highlights
Dry in the north-west, wet in the south-east.
A dry spell from the 5th to the 20th brought a respite from the unsettled weather experienced at the start of December and over the Christmas period.
The changeable weather of November continued into the first few days of December as Atlantic fronts crossed the country. There was rain and gales in Shetland on the 1st, with a gust of 79 m.p.h. at Fair Isle. Another front brought more rain during the night of 3rd/4th, lingering during the day in the east.
A major change in the weather took place on 5th as a Scandinavian anticyclone directed an east to south-easterly airstream across Scotland for the next two weeks. It was often cloudy, which prevented temperatures from falling very low. However, clear skies prevailed in the west on 11th and 12th, and more widely from the 17th to the 19th. During the latter spell severe frost developed, with a maximum temperature of -3 °C at Strathallan on the 19th. The following morning the temperature had fallen to -8 °C at Dumfries and -8.6 °C at Altnaharra.
From the 21st to the 27th, low pressure in the mid-Atlantic pushed a series of fronts across the country, bringing dull, mild, and often wet weather. On the 23rd gusts reached 75 m.p.h. at Fair Isle, there was 37 mm of rain at Enochdhu, and the temperature reached 14.6 °C at Lochcarron.
During the last few days of December low pressure remained in mid-Atlantic, but fronts travelled east over England, leaving Scotland in a drier east-south-easterly airstream. It was mostly cloudy, but breaks in the cloud allowed some night frosts in the north.
Northern Ireland diary of highlights
Dull and dry.
With the exception of some parts of County Down the period from the 4th to 20th was fairly dry throughout the province, while the wettest days were recorded on the 1st, 3rd, 21st, 22nd, and 29th. Many areas experienced nearly two thirds of the month in which little or no sunshine was recorded, but despite this December recorded above average durations. Across Northern Ireland overall mean temperatures were above normal, indeed night-time temperatures were rarely below average.
1st to 3rd Although a mild start to the month it was also wet and dull. Moderate and at times heavy rain, with some locally heavy downpours occurred on the 1st and 3rd.
4th to 16th On the whole this was a fairly dry period with some light showers occurring, producing only slight amounts of rainfall throughout. However parts of County Down recorded some heavier falls on the 7th, 12th and 13th. Temperatures were around or slightly below normal while widespread ground frosts recorded on up to seven occasions. No sunshine was recorded on the 6th, 8th and between the 12th and 15th. In contrast the brightest period of the month occurred between the 9th and 11th with some areas recording over six hours of sunshine alone on the 9th.
17th to 20th Over this period mainly dry conditions prevailed almost everywhere. Though this was the coldest period during the month with both day- and night-time temperatures recording below average values. Sunny conditions prevailed on the 17th and 18th but little or no sunshine was recorded during the rest of the period.
21st to 25th A mild south-westerly airflow brought exceptionally mild conditions for this time of the year. Bands of moderate and at times heavy rainfall occurred throughout. The highest falls occurred over the Mourne mountains area of County Down which recorded more than 50 mm of rainfall over the 21st and 22nd alone.
26th to 31st Rather unsettled conditions concluded the remainder of the month. Bands of rain and showers tracked across the province to give some moderate to heavy falls on the 26th, 28th and 29th.