The averaging period used for the following assessment was 1981-2010.
May began unsettled and windy with low pressure in charge, but by the 5th a warmer and more settled pattern became established with high pressure close to the UK. For much of the rest of the month an easterly flow prevailed and brought plenty of fine, warm and sunny weather, although it was often cooler near North Sea coasts, and scattered thundery showers sometimes affected western and southern areas. It was particularly warm in the second week. This pattern was interrupted by a brief colder interlude mid-month and an unsettled spell from the 17th to 22nd, but warm and sunny weather re-established itself in many western areas during the last week.
The UK mean temperature was 11.3 °C, which is 1.0 °C above the 1981-2010 long-term average. All regions were between 0.5 and 1.5 °C warmer than average. Rainfall was 88% of average, and it was drier than average in south-west England, eastern Scotland and the far north of England, but wetter than average in parts of southern England and western Scotland. Sunshine was 113% of average, and it was particularly sunny in western Scotland and north Wales, but sunshine was near or slightly below average in some counties bordering the North Sea.
The UK monthly extremes were as follows: A maximum temperature of 27.7 °C was recorded at Plockton (Ross & Cromarty) on the 9th. A minimum temperature of -5.7 °C was recorded at Tulloch Bridge (Highland) on the 14th. In the 24 hours ending at 0900 GMT on the 2nd, 81.2 mm of rain fell at Alltdearg House, near Sligachan (Isle of Skye). A wind gust of 53 knots (61 mph) was recorded at South Uist (Western Isles) on the 2nd.
The satellite image below shows the UK on 9 May 2016. It was a cloud-free day across most of Scotland, Northern Ireland and northern and eastern England with many locations recording around 14 hours of sunshine, with 14.7 hours at Stornoway Airport (Western Isles) and 14.8 hours at Dyce (Aberdeen) and Morecambe (Lancashire). The temperature reached 27.7 °C at Plockton (Wester Ross), 26.7 °C at Skye, Lusa and 24.7 °C at Quidnish, Harris (Western Isles). The extensive snowfields across the Cairngorms are clearly visible. Copyright Met Office / NASA
May was a relatively quiet month for severe weather, with the exception of some heavy thundery showers at times. They were quite widespread on the 7th, when there were reports of trains being disrupted between Leicester and Nuneaton due to a lightning strike, but otherwise few impacts were noted.
Heavy showers, and some longer outbreaks of rain in the south, brought more widespread impacts on the 11th. Impacts were noted on the M4 in southeast Wales during the Wednesday morning rush, roads near Lewisham Station were impassable due to deep water and the first day of the Royal Windsor Horse Show was cancelled due to weather for the first time in its history. Woking was notably affected, where a number of houses were flooded and a rest centre was required to shelter some evacuated residents. In addition three schools in the area suffered flooding and were required to close. There were also reports of vehicle collisions with fallen trees overnight near Addlestone. More road flooding was reported in SE Wales during the late afternoon and evening, particularly in the Cardiff area.
After a long quiet spell, lightning strikes on the 27th caused some short-term power cuts in Pembrokeshire, and some flooding was also reported in Powys, with the A40 being closed completely and also in Glenneath, where FRS assistance was needed in several incidents. On the 28th, there were roads and an animal hospital reported to be flooded in Sussex. The Fire Service in Brighton reported increased call volume from flood-related incidents and urged the public to heed Met Office weather warnings. South Wales saw more flooding too, with road flooding in Carmarthenshire and the Fire Service being called out to a number of incidents.
On the 31st, flooding was reported in Southend and Canvey town centres, on the M25 and other roads in the south-east and East Anglia- and several fallen trees were reported to have blocked roads in the warning area. A landslip blocked the rail line between Strood and Tonbridge causing disruption for much of the day.
England diary of highlights
May began unsettled with westerly winds, and there was another brief changeable spell between the 17th and 23rd. Otherwise it was a generally warm month with frequent easterly winds, and often sunny except for North Sea coasts.
The mean temperature for May was 0.9 °C above the 1981-2010 average. Rainfall was 87% of average, with below-average rainfall in the south-west and in the far north, but there was a belt of above-average rainfall extending westwards from the Thames Valley. Sunshine was mostly above average except in some eastern coastal areas, with 110% of average overall.
1st to 6th:
The 1st was dry, sunny and warm in the south-east, but turned cloudy elsewhere, as a belt of rain spread south-eastwards, turning light and patchy by evening. Rain affected all parts on the 2nd, and then brighter showery conditions spread into the north and Midlands. The 3rd was mostly dry and bright with average temperatures, though central and northern parts had showers early in the day. The 4th and 5th were dry and sunny everywhere, and it turned warmer. The sunshine was somewhat hazier on the 6th, particularly in the west, but it was very warm with some places exceeding 20 °C.
7th to 11th:
It was very warm again on the 7th except in the north-east, with some thundery showers over the west Midlands late in the day. The 8th was cloudy in the south-west, while showers faded in central areas, but otherwise it was dry, sunny and very warm away from north-eastern coasts, with a maximum of 27.1°C at St James's Park and Northolt (London). The 9th continued sunny and warm for most, but it was cooler on the east coast and cloudier with rain, accompanied locally by thunder in the far south-west. The rain spread north-eastwards on the 10th giving a cooler and wet day for most of the country, with only the far north staying warm, dry and sunny. The 11th continued dry and sunny in the far north and cloudy elsewhere, with rain or showers, heaviest over southern areas leading to localised flooding.
12th to 16th:
Rain cleared the south-west by afternoon on the 12th, leaving a dry, sunny and warm day for most, but it was cooler and foggy on the east coast, and scattered thundery showers developed in the south. The 13th remained warm with scattered thundery showers near the south coast, but it was cooler elsewhere, with cloud and scattered light showers in the east but plenty of sunshine in the west and south. After a cold start in some places on the 14th with -4.7°C at Shap (Cumbria), it was a cool day with isolated showers down the east coast, but mainly dry sunny weather elsewhere. The 15th was dry and generally sunny with near-average temperatures. The 16th was warmer and remained dry and mainly sunny.
17th to 23rd:
The 17th had a dry bright start, especially in the east, but cloud and rain spread from the west. The 18th was cool and cloudy down the spine of England with rain slowly moving east, but it was brighter with some showers in the south-west. The 19th started foggy in many eastern coastal areas but dry and bright elsewhere, then rain spread from the west from late morning, heaviest in the north, light and patchy in the south. There was a mix of sunshine and showers in the north early on the 20th, otherwise it was dry but mostly cloudy, and persistent rain spread from the south-west during the evening, reaching all parts except the south-east and East Anglia. The 21st was mostly cloudy with patchy rain but a belt of heavy rain crossed the north, and another area moved east across the south coast, and thunderstorms affected the far south-east. The 22nd was a day of sunshine and widespread heavy and locally thundery showers. The 23rd was dry for many parts with sunny spells, but sharp showers developed along a band from the Pennines to the south coast.
24th to 27th:
The 24th was dry and sunny, especially in the south-west. The 25th was cool and cloudy except in the south-west, and rain spread into eastern coastal areas. The 26th turned dry and sunny in the south but it remained cool, cloudy and wet over the Midlands and north. The 27th was generally bright or sunny except in the north-east, with some locally heavy showers over the south into the evening and overnight; 51.9 mm of rain was recorded at Ringmer Bishops Lane (Sussex) in the 24 hours ending 0900GMT on the 28th.
28th to 31st:
The 28th started dry for most, with early showers over the West Midlands dying out, more showers over the southeast turning thundery in the afternoon before clearing, then showers developing over the southwest and turning thundery too into the evening. The 29th was cloudy in many eastern areas with fog and drizzle down the east coast, but dry, sunny and warm in the west. The 30th was similar, but cloudy conditions extended further west and showery rain spread into the south-east during the afternoon and evening. It was sunny in the west on the 31st with 15.4 hours of sunshine at Morecambe (Lancashire), but cloudy in the east with heavy rain moving west, including thunderstorms across East Anglia and the Kent coast in the early morning.
Wales diary of highlights
May started wet and windy with westerly winds, and there was another unsettled interlude between the 17th and 22nd. Otherwise it was a generally warm month with frequent easterly winds, and plenty of dry sunny weather, especially in the north, but also some thundery downpours, particularly in the south.
The mean temperature for May was 1.2 °C above the long-term average. Rainfall was mostly above average in the south and below average in the north, with 99% of average rainfall overall. Sunshine was 118% of average, and it was particularly sunny in the north, but with close to average sunshine in the south-west.
1st to 6th:
It was cloudy and wet on the 1st, but turned drier by the evening. The morning of the 2nd was also dull and wet, but the rain cleared to leave sunshine and scattered showers, and it was windy with a gust to 54 mph at Capel Curig (Gwynedd). It was mostly dry and sunny on the 3rd although there were a few well-scattered showers. The 4th and 5th were warm, dry and sunny throughout. The 6th was also dry and warm, with temperatures in the high teens, but it was cloudier, particularly along western coasts.
7th to 11th:
It was warm again on the 7th, but cloudy, and many places were wet, with thundery showers especially affecting the north-west in the early evening. There were isolated showers on the 8th, but otherwise it was quite sunny and very warm. The 9th was very warm, with 25.5°C at Prestatyn (Clwyd), but it was cloudier, particularly in the south, with some rain or showers, which turned thundery in the afternoon. It was generally cloudy, wet and considerably cooler on the 10th. The 11th had further cloud and rain, which turned heavy in the south from late afternoon, resulting in 31.4mm at Cardiff (South Glamorgan.)
12th to 16th:
There were some showers in the south early on the 12th, but otherwise it was dry, sunny and warm. It was cooler on the 13th but dry and sunny, with some late afternoon showers in the south. It was sunny and dry for all parts on the 14th, though quite cool. There was a cool start to the 15th, with -1.4 °C at Sennybridge (Powys), but the day was dry and sunny and generally a little warmer. The 16th stayed dry and sunny throughout, and turned warm.
17th to 22nd:
The 17th started dry and bright, and it was quite warm, but cloud and rain soon spread from the west. The 18th was a day of sunshine and showers but the showers died out during the evening. The 19th started dry and bright but rain spread eastwards across the country around midday, followed by brighter showery weather. The 20th started dry, bright and quite warm, but it turned wet everywhere from early evening. The 21st was generally cloudy except in the far north, with patchy rain turning heavy and persistent by midday, more especially in the south and west, but it turned drier into the evening. The 22nd was sunny but with scattered showers, which particularly affected the west.
23rd to 26th:
The 23rd had some isolated showers in the south, but elsewhere it was dry and quite warm with sunny spells. The 24th was a dry sunny day and it turned warmer. The 25th was dry but much cooler and cloudier, particularly in the east. The 26th was warmer, with some sunny spells for the west and south, accompanied by late evening showers over Pembrokeshire, but it was cloudy with some rain in the north.
27th to 31st:
The 27th was sunny in the north but cloudier in the south, with widespread, locally heavy and thundery showers. The 28th was generally sunny, but with scattered sharp showers, which became organised and thundery through Dyfed and Gwynedd during the afternoon. It was dry and sunny on the 29th and the 30th, and Valley in Gwynedd recorded 15.1hrs of bright sunshine on the 30th. It was sunny again on the 31st with temperatures exceeding 23 °C in some places, but cloud spread from the east during the evening.
Scotland diary of highlights
May began changeable with at times strong westerly winds, and there was a further spell of westerlies between the 17th and 22nd. Otherwise, easterly winds blew frequently and brought plenty of warm, dry and sunny weather, especially to the west. It was particularly warm in the west during the second week.
The mean temperature for May was 1.0 °C above the 1981-2010 long-term average. It was a dry month in the east, but rainfall was generally near or above average in the west, with 86% of average overall. Sunshine was 115% of average, and it was particularly sunny in the west, but with close to average sunshine in the north-east.
1st to 5th:
The 1st was cloudy and wet, with 81.2 mm of rain at Skye Alltdearg House (Invernesshire), but there was a drier interval in the afternoon before more rain spread from the west. The 2nd started wet with gusty winds, then the rain cleared south to leave sunshine and widespread showers, some heavy and thundery, and a gust of 61 mph was reported in South Uist (Western Isles). The 3rd was also windy with sunshine and showers, although the showers became fewer after midday. The 4th was windy and quite cloudy, with some rain in the west. The 5th had patchy rain and strong winds over the Hebrides, and it was quite cloudy in Lothian, but elsewhere it was dry and warm with plenty of sunshine.
6th to 12th:
The 6th was a dry day, and it was warm and sunny except near the east coast. The 7th was cloudier, with some rain across Argyll and the north-west Highlands while other areas stayed dry. Early showers became confined to northern areas on the 8th, otherwise it was dry and warm with some sunny intervals. The 9th was dry and sunny everywhere, and very warm away from the east coast, with Plockton (Ross & Cromarty) reaching 27.7 °C. The 10th continued dry and sunny, though generally not quite as warm as the previous day. The warm dry sunny conditions persisted on the 11th, and again for most on the 12th, although showers developed in central areas on the afternoon of the 12th.
13th to 16th:
The 13th was cooler and generally cloudier, though still with some sunny intervals, and some light rain in the south in the morning. The 14th started cold, with -5.7 °C overnight at Tulloch Bridge (Invernesshire), and a sunny day followed for most, although the north saw some showers in the evening. The 15th had early showers in Shetland and it was quite cloudy in the north, but sunny in the south. The 16th was dry and quite warm, cloudy in the north but sunny in the south.
17th to 22nd:
The 17th started bright and quite warm in the east, but cloud and rain spread from the west during the afternoon. The 18th was generally cloudy and showery, and it was quite warm in the south-east but cooler elsewhere, with some persistent rain in the north. It was cool and cloudy on the 19th with rain in the west spreading eastwards to all areas by mid-afternoon, and turning foggy on the east coast. The 20th was sunny and quite warm near the east coast, with showers elsewhere, but persistent rain spread to all areas from the south-west from late afternoon. The 21st had a generally cloudy and wet morning, followed by brighter conditions with widespread showers. The 22nd was a day of sunshine and showers, and it was warm across the Borders and Central Lowlands, and sunny in the far north, but with frequent showers across the Grampians and north-west.
23rd to 31st:
The 23rd was also showery over the Grampians but mostly sunny elsewhere and warm in places. The 24th was mostly dry, particularly warm in Argyll and very sunny over the Western Isles. The 25th started sunny and dry, but it turned cloudy in eastern areas, with rain spreading into the Borders. It was cool, cloudy and wet in the Central Lowlands on the 26th but sunny and dry in the north-west. Cool and cloudy over the east on the 27th with some patchy light rain, but warm and sunny further the west, Stornoway (Western Isles) recording 15.9 hours of sunshine. After a generally cloudy start to the 28th with showers over the Western Isles, it turned brighter and warm everywhere, but the showers persisted over the north-west. The 29th was generally warm and sunny, but with thundery showers over the north-west Highlands and parts of Grampian. The 30th started cloudy away from the Western Isles; the cloud burned back eastwards during the day, leaving warm sunshine, but showers developed through the Central Belt in the afternoon. The 31st was cool with persistent cloud and drizzle near coasts in the north-east, but sunny and warm inland and in the south, with 16.0 hours of sunshine at Leuchars (Fife), the month's highest.
Northern Ireland diary of highlights
May began unsettled and windy with westerly winds, and there was a further unsettled spell from the 17th to 22nd. Otherwise, it was a generally warm, dry and sunny month with frequent easterly winds, though with some scattered thundery showers at times.
The mean temperature for May was 1.0 °C above the long-term average. Rainfall was 81% of average, and most of the country had near or slightly below average rainfall, with the north-east generally driest relative to average. Sunshine was 120% of average, and it was particularly sunny in the west of the Province.
1st to 4th:
The 1st was cloudy with near-average temperatures, with rain early and late in the day and a drier interval around midday. The 2nd started cloudy and wet, clearing to sunshine and showers from late morning; some showers were heavy and thundery, and it was windy with gusts up to 52mph at Killowen (Down). The 3rd again saw sunshine and showers, but the showers faded out after midday, and the evening was dry. The 4th was a warmer but increasingly windy day with early sunshine followed by cloud and patchy rain.
5th to 12th:
The 5th was sunny, mostly dry and warm, and it remained dry, sunny and warm on the 6th. The 7th was cloudy and wet, the rain becoming patchier in late evening. The 8th dawned with patchy fog, clearing to leave a sunny, warm day. The 9th was very warm with hazy sunshine (25.3 °C at Edenfel (Tyrone)), with just a few showers in the south-east. The 10th was another dry sunny day in the north, but it clouded over from the south with some rain by evening. The 11th was quite warm with sunshine and showers, drying up in the evening. Apart from a few showers in the south-east early on the 12th, it was dry, sunny and warm.
13th to 16th:
The 13th was another warm day in the west, but rather cooler than of late in the east, while all parts were dry with plenty of sunshine. The 14th was much cooler everywhere, but it remained dry and sunny. The 15th started cold in most places with a minimum of -3.2°C at Katesbridge (Down), and it was a cloudier day near the north coast, but elsewhere it was another dry sunny day. The 16th was dry with more cloud in most places, but it remained sunny in the south, where it also turned warmer.
17th to 22nd:
Although the 17th was quite warm, there was a marked change in the weather pattern, with cloud and rain spreading from the west. The 18th was cooler and mostly cloudy, with occasional sunshine and some isolated showers. The 19th started cloudy and wet, then turned brighter with some showers. The 20th started bright with a few showers, but it turned wet from around midday, with 24.8 mm of rain at Magilligan (Londonderry). Rain cleared the north on the 21st, followed by sunshine and showers. The 22nd was a day of sunshine and showers, the showers heavy in Antrim, and it was quite warm away from coasts.
23rd to 31st:
The 23rd was cloudier but still with some sunny intervals, and some showers in the Spernins. The 24th was a warm, dry and sunny day. The 25th started sunny and dry, but turned cloudy from the east, with some late evening rain. The 26th was overcast and cool with patchy rain throughout the day. The 27th also dawned cloudy with patchy rain, but it became drier and brighter during the afternoon. The 28th was a warm and bright day with showers, mainly in the west, turning thundery in the evening. The 29th was warm and sunny with some scattered showers, these mainly in the south. Patchy low cloud and fog on the 30th cleared away to leave a warm sunny day with a few showers developing over Fermanagh in the afternoon, and 15.5 hours of sunshine recorded at Ballywatticock (Down.) The 31st was another dry sunny day following the clearance of early low cloud, and temperatures reached 21°C in many places.