2017 was warmer than average for the UK as a whole, with temperatures 0.7°C above the 1981-2010 long-term average, ranking as the fifth warmest year in the historical UK series since 1910.
The year began dry and settled. The start of January was cold and frosty, and some snow during the second week. The second half of the month saw a prolonged settled spell but it turned mild, cloudy and changeable towards the end of the month and into February. Shortly into February it turned colder again, with some snow in the second week, whilst the second half of the month was generally mild. The 2016/2017 storm season was relatively quiet in terms of wind storms – with none occurring during January and early February. Storm Doris hit the UK on the 23rd February bringing snow and rain to the UK and wind gusts peaking at 94 mph. The final storm of the winter period was Storm Ewan, which brought strong winds, snow and icy conditions to the UK, and especially Ireland, just a few days before spring.
Overall, spring in the UK was warm, sunny and quite dry, especially during March and the first half of April. March was much sunnier and warmer than average across the UK – it was more than 2°C warmer in parts of East Anglia and south-east and central southern England, equalling the mildest March since records began in these parts. Early April was warmer than average although the second half was cooler, with some late overnight frosts and snow flurries occurring across parts of the UK on the 26th. It was also much drier than average for most areas as high pressure dominated for much of the month. However, a weather system bought heavy rainfall to parts of the country just in time for the May Day bank holiday weekend. May was predominantly warm with a few short cooler spells mid-month, with a notable hot sunny interlude between 24th and 26th where temperatures reached the mid to high 20s Celsius. This was followed by widespread thunderstorms on 27th-28th. Overall, it was the second warmest May since 1910.
Summer was relatively wet, indeed it was the 9th wettest summer since 1910, but it was also warmer than average. June began largely unsettled with significant rainfall across most parts of the UK. High pressure began to build after the 10th and exceptionally warm air was drawn up from the south with at least one area in the UK exceeding 30°C from 17th to 21st June – the first time this has happened in June since 1995. The last few days of the month brought fresher conditions. Despite the hot, dry weather mid-month, June was among the wettest on record with 50% more rainfall on average for the whole of the UK. July was generally an unsettled month with occasional periods of fine and dry weather. It began with cloud, rain and cool temperatures, but was particularly warm and sunny on the 17th and 18th, ending with a thundery breakdown. The end of the month was wet and often cool with heavy and persistent rain at time - rainfall across the UK was above average, with parts of central southern and south-east England receiving twice the amount of rainfall for July. August began and ended much as July did, cool with cloud and rain, and only brief intervals of fine weather. There was a fleeting period of warmer weather from the 17th-23rd but overall it was a cool month, with temperatures 0.4°C below the long-term average and rainfall above normal for the UK overall.
Autumn 2017 was rather unsettled, with temperatures close to average. For the most part, September was duller, cooler and wetter than average, with higher temperatures towards the end of the month. It was also windy at times, notably during the passage of Storm Aileen - the first storm of the 2017/18 season - on the 12th and 13th. Most areas were rather dull, dry and mild during October, indeed, it was the equal 8th warmest October since 1910. However, colder temperatures, and the first frosts arrived at the end of the month. Some parts of north and western Scotland, north-western England and Northern Ireland did, however, encounter above average rainfall due to ex-hurricane Ophelia and Storm Brian, the second storm of the season. November was dry and bright for many, but slightly colder than average, mainly at the end of the month. There was a brief period of mild weather on the 20th-22nd, preceding a very wet episode in parts of north Wales and north-west England.
December was just slightly above average in terms of temperature, but there were some cold and frosty periods. Storm Caroline, the third storm of the season, brought strong winds on the 7th, and a wintry spell brought widespread frosts and some snow for parts of the Midlands from 8th to the 16th. It was generally mild on the run up to Christmas, after which there was further snow for some, particularly the north. The end of the year was increasingly unsettled, with Storm Dylan bringing further strong winds on the 30th/31st.