The averaging period used for the following assessment was 1961-1990.
Generally dry and very sunny throughout the UK. A period of high pressure centred on Scotland mid month led to cold conditions with frost and fog at night. Milder and unsettled spells of weather at the start and towards the end of the month, with occasional heavy rainfalls.
This has been the sunniest January in the series (back to 1961) for England and Wales. Very sunny too in Northern Ireland and many northern stations in Scotland broke records.
England and Wales diary of highlights
A very sunny month with temperatures and rainfall near average. A wet and mild start, mainly dry for a fortnight, then colder with a little snow. The fourth week began mild wet and windy but frost and fog returned at month's end.
1st to 4th January began mild and wet as low pressure edged eastwards. Outbreaks of rain and showers were heavy at times particularly in the west.
5th to 11th A complex low-pressure area over the region migrated to southern Scandinavia by 9th. There were scattered showers, some wintry, especially in northern and western areas, however southeast parts were often dry and mainly sunny. High pressure near Iceland then moved to central Scotland by 10th and 11th producing strong and cold east or north-east winds over southern England.
12th to 20th The high pressure then slowly receded east to Leningrad by 18th. The weather was mostly dry and sunny at first under the high pressure, but much colder from the 16th onwards with frost and fog at night. The fog was slow to clear at times in the morning. During the 18th to the 20th weak low pressure systems affected the region with snow falling in places. Some snow flurries were experienced in southern counties during the 18th, while a few centimetres of snow carpeted East Anglia on the 19th and also in places in north-east England. Redesdale (Northumberland) and Redhill (Surrey) recorded -8.0 °C early on the 19th and 20th.
21st to 25th With low pressure to the west and north-west, a very mild, wet and windy period ensued, preceded by some snow in central and northern areas. Sunny periods alternated with bands of rain and showers, some of which were heavy and accompanied by thunder especially in the west and north. A gust of 63 kn was recorded at Llanbedr (Gwynedd) on the 23rd.
26th to 31st After a wet start with outbreaks of rain, sleet and snow the 27th, 28th and 29th were mainly sunny and dry with some fog and frost at night. An occluded front became stalled over England and Wales during the last two days. Although mild in the south-west most places were rather cold with overnight frost, patchy fog and outbreaks of light rain and drizzle.
Scotland diary of highlights
Dry and sunny, especially in the north.
January was a quiet month for weather and was notable for a long anticyclonic spell in mid-month with light southerly winds, hard frosts and sunny days. This contributed to record sunshine totals being reached at many northern stations. It is the third time in the last four months that places in the north of Scotland have broken sunshine records.
The first week was dominated by low pressure to the north, but the main belt of disturbed weather lay well to the south and most of the rain was showery.
The long anticyclonic spell began on the 9th and lasted until the 20th, during which time the main centre of high pressure transferred from northwest of Scotland to Russia. The wind direction was mostly from the south, and this prevented cloud from the North Sea from invading the country. The weather was often sunny by day and frosty by night, with the temperature at Aviemore falling to -13 °C on the 17th.
The last 10 days of the month returned to the cyclonic theme, and was heralded by snow on the 21st as Atlantic fronts encountered the cold continental air. As in the first week, the cyclonic spell was associated with light winds and showers rather than prolonged periods of rain.
Northern Ireland diary of highlights
This was another dry January month.
The period 20th to 25th was wettest and mildest overall, but the two-week period up to 20th was dominated by cold, dry weather. All areas experienced around 10 to 12 quite sunny days, which lifted sunshine totals to well above average across all areas. Temperatures only reached or exceeded 10 °C locally on the 1st and 23rd, otherwise daytime maximum temperatures were typically between 3 °C and 7 °C. Overnight temperatures as low as -6 °C to -8 °C were recorded frequently across some central and western areas between the 14th and 19th.
1st to 7th Generally unsettled with spells of rain or showers, but rainfall amounts mostly small. Mild at first, but turning colder from the 2nd/3rd.
8th to 20th Dry and cold, with widespread moderate, locally severe frosts. Very sunny from the 8th to 14th inclusive, then generally cloudy.
21st to 31st Unsettled, mild and quite wet till the 25th. Then drier and colder with another cold, sunny spell from 26th to 29th. Mild and unsettled again on the 30th and 31st, but with only small amounts of rainfall.