September 2010

The averaging period used for the following assessment was 1971-2000.

UK overview

A changeable month with plenty of rain, especially across the northern half, but also some more settled spells. Although temperatures overall were close to or above normal, there were significant variations with several warm days but also some cold nights and localised frost. Mean temperatures were about 1 °C above normal across Northern Ireland and much of northern England, southern and western Scotland and close to average elsewhere. Rainfall varied from over 150% of the normal amount in much of Northern Ireland, parts of eastern Scotland and northern England to less than 75% of normal in parts of south-east England and the south Midlands. Sunshine duration was generally close to, or somewhat above, average.

A maximum temperature of 24.6 °C was recorded at Gravesend (Kent) on 22nd. A minimum temperature of -4.4 °C was recorded at Tyndrum (Stirling) early on 26th and at Kinbrace (Highland) early on 27th. In the 24 hours ending at 0900 on 14th, 102.6 mm of rainfall was recorded at Seathwaite (Cumbria). A wind gust of 68 mph was recorded at Capel Curig (Conwy) on 15th.

England diary of highlights

After a settled first few days, much of the rest of the month was changeable with showers or bands of rain particularly across northern areas. Generally warm, especially in the first half, but some colder interludes later. Mean temperatures ranged from close to the 1971-2000 normal across southern areas to about 1 °C above normal in northernmost counties. Rainfall varied from over 150% of average in Lancashire and parts of east Yorkshire and Lincolnshire to less than 75% of average in parts of the south-east and the south Midlands. Sunshine amounts were generally close to normal.

1st to 4th:

With an area of high pressure over or close to the UK, the first few days of the month were mainly dry and settled and temperatures widely reached 21 °C each day. Mist and fog developed in places overnight.

5th to 8th:

By the end of the first week, more unsettled weather had taken hold with bands of rain from the west. Outbreaks of heavy rain spread north-eastwards on 6th with over 20 mm in some northern and western areas. In the 24 hours to 0900 on 7th, 32.6 mm fell at Cardinham (Cornwall) and 30.8 mm at Walney Island (Cumbria). Showery conditions developed on 7th with a further 15.6 mm falling at Cardinham.

9th to 15th:

A dry day with some sunshine on 9th was followed by rain spreading to north-western parts on 10th. Rain spread south-eastwards on 11th, clearing the south-east in the evening. Scattered showers followed the rain and affected many areas on 12th, but more persistent rain reached the north-west in the evening. This continued on 13th, with rainfall totals over 20 mm in many north-western areas and 102.6 mm at at Seathwaite (Cumbria). South-eastern areas stayed largely dry. During 14th and 15th, rain spread slowly southwards.

16th to 19th:

After mid-month the weather remained unsettled, but became cooler with some frosty nights. During 16th to 19th there was a mixture of bright spells and scattered showers, although more persistent rain gradually reached the north-west on 19th.

20th to 22nd:

After cloud and rain cleared the north on 20th, these were mainly dry, fine days. The warmest day of the month was 22nd, when temperatures reached 22 °C across many eastern and southern areas and 24.6 °C at Gravesend (Kent). It was cooler overnight though, with mist and fog developing. By the evening of 22nd, rain had reached the far west.

23rd to 30th:

Rain affected most areas on 23rd, but cleared on 24th to leave a dry and bright day for many on 25th. The 24th and 25th were cold days, with temperatures no higher than 11 to 13 °C across much of England. The night of 25th/26th was the coldest of the month, with temperatures falling towards 0 °C and ground frost at places in the west and north. Western parts kept some drier weather on 26th and 27th, but outbreaks of rain affected eastern parts. On 28th, further rain spread into the west, moving eastwards overnight and on 29th when central and eastern areas were wettest with 17.0 mm at High Wycombe (Bucks). The 30th was largely dry with just a few showers in western parts.

Wales diary of highlights

After a fine start, it was a mostly changeable month, with plenty of showers or periods of rain. Some warm days in the first half, but some colder spells later. Mean temperatures were typically 0.5 °C above the 1971-2000 normal. Rainfall was about 25% above normal. Sunshine was some 5% above normal.

1st to 4th:

Fine and mostly sunny for the first few days, with temperatures widely peaking around 21 °C on 2nd and 3rd. Cloud arrived in the west during the evening of 4th heralding a change to more unsettled weather

5th to 16th:

A few showers during 5th. Soon turning cloudy on 6th, with outbreaks of rain into the west during the day. On 7th, sunny intervals and showers, many heavy with thunder and tending to merge into longer spells of rain in the north. Showers developed during 8th, some heavy and thundery. The 9th was a fine day with sunshine and light westerly winds. On 10th, cloud and rain spread in from the west, the rain becoming slow-moving then heavy towards evening; 61.8 mm of rainfall was recorded at Sennybridge (Powys) in the 24 hours to 0900 on 11th. Despite the wind and rain, the temperature at Hawarden (Flintshire) rose to 22.1 °C. During 11th, rain moved away eastwards, and the afternoon was brighter with sunshine and showers. Much of 12th was fine and sunny. Some rain arrived in the north early on 13th, spreading to all areas on 13th and 14th. This became heavy and persistent at times, giving 48.8 mm at Capel Curig (Conwy) in 24 hours to 0900 on 14th. There was a dry start to 15th, before some showers spread from the north. A windy day, gusting to 68 mph at Capel Curig. There were showers on 16th, developing quite widely during the morning.

17th to 19th:

After a cold start, 17th was mainly dry and sunny. The 18th again started cold with a ground frost before cloud spread in from the west. The 19th again dawned cold, but rain spread in during the day. This persisted in the north and west, with 37.4 mm recorded at Capel Curig in 24 hours to 0900 on 20th.

20th to 25th:

The 20th saw further occasional rain, mainly in the west during the morning. On 21st, a band of rain moved slowly south-eastwards to lie through mid-Wales by evening, some of the rain heavy. Further heavy rain at first on 23rd, replaced by sunshine and showers during the afternoon; 42.8 mm of rain was recorded at Rhyl (Denbighshire). The 24th was rather cloudy with further light showers and sunshine later and 25th was mainly fine. These were cold days, with temperatures typically no higher than 10 to 12 °C.

26th to 27th:

Cold again on 26th with local air frost early, the temperature falling to -1.7 °C at Sennybridge (Powys), then dry with bright spells. The 27th was bright and dry, and stayed dry throughout.

28th to 30th:

After a dry start on 28th, cloud and rain spread in from the west. More rain moved eastwards overnight into 29th, but it became brighter later with a few showers in the west. The 29th/30th was another cold night under clear skies. The 30th was mostly dry with sunshine but a few sharp showers. During the evening, cloud and rain spread from the west.

Scotland diary of highlights

A changeable month, with some warm days in the first half but localised frosts in the last week. Mean temperatures ranged from close to the 1971-2000 average over the Northern Isles to about 1 °C above average over the south and west. Some overnight temperatures in the last week were notably low for September, in places the lowest for 20 to 30 years. Rainfall was close to average in most areas, but over 150% of normal fell in north Moray, north Aberdeenshire and parts of Fife. Sunshine was generally close to normal, the main exception being the Northern Isles and south-west Scotland which were about 20 to 30% above normal.

1st to 5th:

The 1st was mostly cloudy with patchy light rain. Dry and mainly sunny from 2nd to 4th, and becoming warm in places with 24.5°C at Kinlochewe (Highland) on 3rd. Rain reached western areas late on 4th. The 5th was mostly dry with sunny spells, especially in the north, and the temperature reached 21.9 °C at Lusa (Skye).

6th to 13th:

On 6th rain spread from the south-west, giving 40.4 mm at Port Ellen (Islay) overnight by 0900 on 7th. The rain spread further north on 7th, producing 33.8 mm at Aboyne (Aberdeenshire) in 24 hours to 0900 on 8th. Sunshine and thundery showers followed to the south, with 31.6 mm at Carterhouse (Borders) in these 24 hours. Strong easterly winds and high tides caused some problems along the east coast. The 8th was mainly dry with some warm sunshine, the temperature at Lusa reaching 21.6 °C. Sunny spells and a few showers on 9th but some persistent rain over Shetland. Rain spread eastwards on 10th, then brighter with showers in the west. Warm in some eastern parts, with 22.2 °C recorded at Kinloss (Moray). A band of rain moved eastwards early on 11th followed by showers, these heavy at times. Sunny intervals and a few showers on 12th before rain spread from the west in the evening. A mainly cloudy day on 13th with rain heavy at times in the north-west, with 49.6 mm recorded in 24 hours at Tyndrum (Stirling).

14th to 23rd:

The 14th was bright with showers, frequent and heavy in the north and west. The 15th was cool with sunshine, showers and strong winds with a gust of 60 mph at Drumalbin (Lanarkshire). Frequent showers continued over the north on 16th, with north-westerly gales and a gust of 56 mph at Baltasound (Shetland), but mainly dry and sunny further south. Less windy in north on 17th with further blustery showers, but again drier and brighter further south. Bright in the north and south-east on 18th, cloudy with some rain elsewhere. Outbreaks of rain on 19th, with 24.6 mm in 24 hours at Aultbea (Highland), but drier and brighter in the south-east. On 20th a band of rain cleared northwards, followed by scattered showers. Clouding over from the west on 21st with outbreaks of rain, these heaviest and most persistent in the west. Rain or showers on 22nd, some thundery, with 59.6 mm recorded at Bishopton (Glasgow) and 67.0 mm at Hunterston (Ayrshire) in 24 hours to 0900 on 23rd. Persistent heavy rain over the north-east on 23rd, with 56.4 mm in 24 hours to 1900 at Rosehearty (Aberdeenshire). Scattered showers across the rest of the south and east, and drier in the west.

24th to 30th:

Mainly dry from 24th to 26th with sunny spells and a cold northerly wind. Scattered showers affected the north-east giving the Cairngorms a fresh covering of snow. Some overnight frosts developed, with temperatures of -4.2 °C at Tulloch Bridge (Highland) and -4.4 °C atTyndrum (Stirling) early on 26th and -4.4 °C at Kinbrace (Highland) early on 27th, the coldest September nights here for over 20 years. More cloud on 27th but mainly dry. Rather cloudy on 28th with outbreaks of rain, more especially during the afternoon. A band of rain, heavy at times, moved eastwards on 29th followed by drier, brighter conditions. The 30th was a mainly dry day with sunshine and isolated showers.

Northern Ireland diary of highlights

After a fine start, it was a mainly unsettled month with showers or longer spells of rain. There were some warm days in the first half, but cold nights in the last week with frost. Overall, mean temperatures were about 1 °C above the 1971-2000 average. Rainfall ranged from about twice the average in much of Fermanagh and Armagh to close to average near the coasts of Antrim and Down. It was the wettest September since 1999 over Northern Ireland generally. Sunshine duration was close to normal.

1st to 10th:

The 1st was mainly dry and rather cloudy with a top temperature of 21.3 °C at Castlederg (County Tyrone). Dry and sunny on 2nd and 3rd, with temperatures reaching 22.7 °C at Derrylin (County Fermanagh) on 2nd and 23.4 °C at Castlederg on 3rd. Rather cloudy on 4th with outbreaks of occasionally heavy rain spreading north-eastwards. Cloudy again on 5th with patchy rain, this becoming more persistent during the evening. Heavy rain continued throughout 6th and southern areas collected more than 50 mm, with 90.2 mm at Killowen (County Down) and 94.8 mm at Lough Fea (County Tyrone) in the 48 hours to 0900 on 7th. A brighter day on 7th but with some heavy showers. Sunshine on 8th with heavy showers in the west. Sunny spells and a few showers on 9th, with the temperature rising to 22.5 °C at Killowen, before rain arrived during the evening. Overnight rain then dry with some sunshine on 10th.

11th to 20th:

Sunny intervals and showers on 11th, some heavy with thunder. Sunny intervals and a few showers on 12th before rain spread from the west in the evening. A cloudy day on 13th with outbreaks of rain, these heavy at times before clearing in the evening. Sunshine and showers from 14th to 16th. There were still a few showers on 17th but otherwise it was dry with sunny spells. Cloudy with outbreaks of rain on 18th, giving 18.2 mm at Lough Fea. A bright start to 19th, before occasional rain later. Cloudy with some rain at first on 20th but then dry with sunny spells developing.

21st to 30th:

Generally cloudy with outbreaks of rain on 21st. Brightening up on 22nd, but the sunshine set off thundery showers. Rather cloudy on 23rd with scattered showers, heavy at times in the east. Much drier and brighter on 24th. A clear night led to the temperature at Katesbridge (County Down) falling to -1.4 °C. The 25th was dry but cloudy and cool. The cloud broke up on 26th and 27th allowing some sunny spells to develop, and the temperature at Katesbridge fell to -2.2 °C early on 27th. Rather cloudy on 28th with outbreaks of rain, more especially in the afternoon. The 29th and 30th were mainly dry and bright with just a few showers.

Last updated: 27 February 2013