The averaging period used for the following assessment was 1981-2010.
May was another warmer than average month. There were some spells of dry and warm weather for many parts of the country early in the month, around the middle of the month and again right at the end, but these were interspersed with more unsettled conditions bringing cloud and rain. A low pressure system passing through on the weekend of 10th to 11th saw some unusually strong winds for the time of year along the south coast. The latter part of the month was less settled, often overcast, and brought abundant rainfall - some of it in the form of thundery showers - for many areas, most especially East Anglia and other eastern counties of England on 26th and 27th.
The UK mean temperature was 11.2 °C, which is 0.9 °C above the 1981-2010 long-term average. This was largely due to there being many mild nights, whereas daytime maximum temperatures were only a little above average. Rainfall was above average for many, with totals well above average in eastern counties of England and the far west of Scotland; north-east England had its wettest May since 1979. The UK overall received 142% of average rainfall. It was the dullest month in records from 1929 for both Northern Ireland and Western Scotland, and dull also across much of northern England and Wales. However, sunshine totals were closer to average in the south, resulting in 80% of average sunshine hours for the UK overall, making this the dullest May for the UK since 1991.
A maximum temperature of 26.3 °C was recorded at Heathrow (Greater London) on the 19th. A minimum temperature of -5.0 °C was recorded at Cromdale (Moray) on the 2nd. In the 24 hours ending at 0900 GMT on the 11th, 77.6 mm of rain fell at Cwm Dyli (Gwynedd). A wind gust of 68 mph was recorded at Needles Old Battery (Isle of Wight) on the 10th.
There were several instances of heavy rainfall during the month, starting with heavy slow-moving downpours over parts of England on the 1st. An unusually windy spell over the weekend of 10th to 11th in many southern areas led to some local disruption on the roads of south Wales. Some northern areas received various instances of heavy rainfall from 18th onwards, and lightning damage was reported in Wales on the 21st. Some southern areas were also the subject of rainfall alerts from 23rd to 27th. Heavy rain over East Anglia moving into north-east England on 27th to 28th was notable for its amount and duration but saw few impacts.
The month opened with a few days of scattered showers but also some bright weather particularly in the south, but after the 5th it became more unsettled. A return to high pressure then resulted in some fine and warm weather mid-month. The 20th saw a return to unsettled conditions with showers, scattered thunderstorms and some more prolonged spells of rain. The last two days were mainly dry and bright.
The mean temperature for the month was 0.9 °C above the 1981-2010 average. Rainfall overall was 164% of average, but parts of eastern England received in excess of twice the average rainfall for the month; for north-east England this was the wettest May since 1979. Sunshine amounts were below average across northern England and the West Midlands, but nearer average in the south and east, with 91% of average overall.
1st to 4th:
There were widespread showers for many areas in the morning of the 1st although these were restricted to southern areas during the afternoon. The 2nd was generally dry and bright although some light showers broke out in the London area in the afternoon. It was dry and bright again on the 3rd. After some rain in the north-east at first on the 4th it became generally dry apart from a few scattered showers.
5th to 13th:
Mostly dry on the 5th until rain spread across the country from late afternoon onwards. Dry at first for most of the country on the 6th but showers became more widespread through the day. Most areas had showers on the 7th but these slowly died out by evening, while a more general band of rain pushed into the north of England during the afternoon. Another area of rain spread across the country through the day on the 8th, clearing during the evening. The 9th was dry and bright for many although scattered showers broke out in eastern areas in the afternoon with thunderstorms in Norfolk. The showers became more widespread on the 10th, accompanied by a strong westerly wind especially in the south, with Needles Old Battery (Isle of Wight) recording a gust of 67 mph; there were thunderstorms again in Norfolk and Humberside. There were showers in northern and eastern areas on the 11th but the south fared better. The showers were more widespread on the 12th and 13th with thunderstorms in many central and eastern areas.
14th to 19th:
An area of high pressure on the 14th gave a mainly dry, warm and sunny day. The 15th to 18th remained mainly dry with plenty of sunshine and temperatures reaching around 25 °C in the London area. The 19th remained dry, warm and sunny for many areas with Heathrow (Greater London) recording 26.3 °C, although heavy showers broke out in the south-west by late morning and spread slowly east.
20th to 29th:
It was slightly cooler on the 20th with showers, and a few thunderstorms, developing during the day, mainly in south-eastern and north-western areas. The 21st was dry and sunny for most of the country for much of the day but an area of heavy showers spread into the south-east in late afternoon. Low pressure increased its influence on the 22nd with widespread showers and thunderstorms; parts of Lincolnshire recorded up to 20 mm in the space of 4 hours. The 23rd saw more showers, mostly in southern counties. Showers covered a wider area on the 24th, some heavy with thunder in some central and eastern areas; Liscombe (Somerset) recorded 32 mm. The unsettled theme continued on the 25th but showers were now more scattered and mainly in central and western areas. On the 26th there was an area of rain from the Midlands to the south coast for most of the day. An easterly wind became established on the 27th, bringing rain into eastern and some central areas, with parts of Suffolk and Norfolk recording up to 30 mm. The 28th remained cool and unsettled with rain more widespread. On the 29th the showers were more scattered although some were heavy with thunder over the south-west during the afternoon.
30th to 31st:
The 30th was generally dry, with sunny spells by the afternoon. The 31st was also mainly dry, bright and sunny, and feeling warmer.
The first two weeks mostly saw a mixture of sunshine and showers. This was followed by a spell of drier, sunnier and warmer weather in mid-month, before it became more unsettled with some thunderstorms and periods of rain for the latter part of the month. The last two days were fine and dry.
The mean temperature for the month was 0.7 °C above the 1981-2010 average. It was a rather dull and wet month, with 152% of average rainfall overall and just 77% of average sunshine hours.
1st to 12th:
The 1st saw rain spreading from the south-west in the morning, breaking up into showers later with a little sunshine. It was dry on the 2nd with some sunshine in the south-west. The 3rd and 4th were dry and cloudier but with some sunshine in the south-east. The 5th was cloudy with patchy rain developing and becoming widespread by the evening. There was sunshine and light showers on the 6th and 7th. Rain on the morning of the 8th cleared to sunshine and showers later. The 9th was generally sunny with isolated showers. Showers were frequent on the 10th, with more persistent rain in the north giving 57.4mm at Capel Curig (Gwynedd), and a strong westerly wind gusted to 63 mph at Mumbles Head (Swansea). The 11th was wet early on, becoming more showery later. The 12th also saw sunshine and showers, with more extensive showers in the north and east.
13th to 18th:
The 13th was sunny, with any showers dying out by late afternoon. It was dry and sunny on the 14th, and similar on the 15th apart from some light, isolated showers in the north-west. The 16th and 17th were dry, sunny and warm with 22.4 °C recorded at Cardiff Bute Park on the 16th. The 18th was mainly dry and sunny, although more cloud appeared in the west and north later in the day.
19th to 29th:
There were heavy showers and thunderstorms during the 19th, particularly in central and north-western parts. Rain early on the 20th broke up into showers, but these merged into further rain later in the day. The 21st was dry and sunny but with some local heavy showers over Anglesey. Rain moved from the south-east to the north-west in the morning of the 22nd with further periods of rain later in the day. It remained generally cloudy with rain or showers from the 23rd to the 25th. Sunshine and isolated showers on the 26th, with more organised rain moving in from the east later. The 27th and 28th had a band of rain moving across from the east in the morning, followed by showers in the afternoon, with very little sunshine. The 29th saw rain, at times heavy, in the south-east; other areas were dry but cloudy.
30th to 31st:
The 30th and 31st were fine and dry, and warmer, with variable cloud amounts.
It was a generally unsettled month with rain and some heavy and occasionally thundery showers. There were some brief spells of more settled weather mid-month and in the last two days, which saw some higher temperatures for many.
The mean temperature for the month was 1.0 °C above the 1981-2010 average. Due to often overcast conditions, nights were particularly mild and the average minimum temperature for May was the equal-highest in a series from 1910. Parts of Argyll were notably wet, with up to twice the normal May rainfall in some areas. Rainfall in other areas was near average, but slightly below for Fife and Aberdeenshire, with an overall figure for Scotland of 118% of normal May rainfall. It was a dull month, particularly for Western Scotland which had its dullest May in a series from 1929. Overall sunshine hours were only 66% of average.
1st to 13th:
Rain in the south on the 1st gradually died out during the afternoon. Mostly dry on the 2nd except for early rain in the Central Belt. Dry for most areas on the 3rd but rain arrived in the north-west later. Most places had showers or longer spells of rain on the 4th. After a generally dry start on the 5th, rain spread to most areas through the day. Showers or longer spells of rain for most places on the 6th with only the south staying mostly dry. Again, showers or longer spells of rain on the 7th, especially in the south in the afternoon and evening, with 16.8 mm recorded at Dunstaffnage (Argyllshire). It was mostly dry at first on the 8th but showers developed during the day with a more general band of rain crossing the country in the afternoon. Another mainly dry start on the 9th before showers developed, heavy at times, especially in the north. It was unsettled on the 10th and 11th with frequent heavy showers in most areas, but these became mostly confined to the west on the 11th. It was a bright day with heavy showers for most areas on the 12th. Bright again in many places on the 13th but heavy and thundery showers built up through the day especially in the east.
14th to 16th:
Mainly dry and bright in the east on the 14th in the east, but some rain in the west. Warm on the 15th with patchy rain in the east, especially the north-east, but mainly dry in the west. It was mainly dry and warm on the 16th apart from some rain in the north-west, with a maximum temperature of 21.6 °C at Edinburgh, Royal Botanic Gardens.
17th to 29th:
A dry start on the 17th but rain, heavy at times, spread into the west through the day with 48.8 mm recorded at both Cluanie Inn and Achnagart (Ross-Shire). More rain in the west on the 18th, but mainly dry in the east. It was mainly dry at first on the 19th, but with some rain in the west, and heavy thundery showers built up later in the day. It was a foggy day in the east on the 20th, with some rain in the west and scattered showers across the country through the day. On the 21st a narrow band of rain moved north up the west coast in the morning; it was brighter and warmer in the east. Rain moved north along the east coast on the morning of the 22nd, with sunshine and less cloud further west. Light showers and more cloud in the south-east and far north with broken cloud and sunshine through the central region on the 23rd. Cloud and rain in the east during the afternoon of the 24th with more sunshine to the west. The 25th saw some heavy and thundery showers during the afternoon, particularly in the Central Belt; Edinburgh Gogarbank recorded 26.2 mm. All areas had sunshine and showers on the 26th. The 27th had light rain in the east, becoming drier with showers for the south-west and parts of the Highlands later, and more sunshine in the west. Eastern and central areas saw patchy rain during the morning of the 28th, with a more organised and heavier band of rain crossing from the south-east to the west in the afternoon. The 29th started dull with patchy drizzle particularly in the south, but drier and sunnier conditions spread from the north during the day.
30th to 31st:
Dry and bright on the 30th as pressure built across the country. Mainly dry and warm again on the 31st with 22.2 °C recorded at Cromdale (Moray), but there was some patchy rain in the north-west later.
There were some brief spells of settled and generally fine weather in the middle and at the end of the month, but otherwise it was often rather unsettled and cloudy with showers or longer spells of rain.
The mean temperature for the month was 1.1 °C above the 1981-2010 average. Due to often overcast conditions, nights were particularly mild and the average minimum temperature for May was the highest in a series from 1910. Rainfall overall was above average, but not exceptionally so at 125% of average. It was the dullest May for Northern Ireland in a series from 1929 with only 62% of average sunshine hours.
1st to 4th:
There was some heavy rain overnight into the 1st which became more showery before dying out to leave a mainly dry afternoon. The 2nd was a dry, cloudy day, and the 3rd started dry before some showery rain for most by the afternoon. Rain was confined to the north at first on the 4th but covered most areas in the afternoon.
5th to 13th:
There was rain or showers throughout on the 5th, most persistent in the afternoon. Showers developed from mid-morning on the 6th with more prolonged, heavy rain later. The 7th was dull and wet in many areas. Rain or showers continued through the 8th and overnight into the 9th but showers became more scattered during the day. Overnight rain gave way to frequent showers feeding in on the north-westerly wind on the 10th. Showers continued into the 11th, but ceased in the afternoon away from the south. Showers throughout on the 12th, most frequent and heavy in the afternoon with 33.4 mm recorded at Castlederg (County Londonderry). Sunshine and showers on the 13th, with showers less frequent in the north.
14th to 17th:
Showers were more scattered on the 14th but it remained generally cloudy. The 15th and 16th were mainly dry, sunny and warm, with the temperature reaching 22.3 °C at Helens Bay (County Antrim) on the 16th. It was cloudier on the 17th with some rain reaching the north.
18th to 29th:
Most places were dull and wet on the 18th, with further heavy rain overnight into the 19th which cleared away for a time before another band of heavy rain and thunderstorms spread into eastern areas later. The 20th saw further spells of rain affecting most areas with the east receiving most. The 21st was mainly dry and sunny. Scattered showers for the 22nd and 23rd, some heavy in the west on the 22nd. On the 24th and 25th it was dull with heavy showers in the south-east, but brighter and drier further north and west. It was showery in the north on the 26th, but drier to the south-east. The 27th and 28th were mostly dry and sunny but saw scattered showers in the afternoon. Overnight rain cleared during the morning of the 29th, leaving behind a few showers.
30th to 31st:
The last two days of the month were dry with sunny spells as high pressure brought generally fine conditions and higher temperatures.
Last updated: 7 July 2015