The averaging period used for the following assessment was 1961-1990.
Mean temperatures generally close to average across England, Wales and Northern Ireland, but slightly above average across Scotland. Wales and Northern Ireland had their coolest September since 1994. A very wet month across the Midlands and north-east England, with some stations in Northumberland recording around 300% of their average rainfall. In contrast, northern areas of Scotland had well below average rainfall. A generally dull month across the UK, with exceptionally below average sunshine across south-west Scotland.
Stradbroke (Suffolk) recorded a maximum temperature of 24.0 °C on 1st. Tulloch Bridge recorded a minimum temperature of -2.1 °C on 22nd. There were high 48-hour rainfall totals in Northumberland on 5th/6th with Goldscleugh recording 225.6 mm, Birkside 158.8 mm and Chillingham Barns recording 158.3 mm. A wind gust of 68 mph was recorded at Berry Head (Devon) on 5th.
England diary of highlights
Unsettled and wet through the first half of the month, but much drier and brighter through the second half.
1st to 4th: An area of low pressure tracked eastwards across Scotland with weather fronts crossing England. This brought showers or longer spells of rain for all parts, which were heavy and thundery at times. Flooding was reported in parts of the south-west on the night of the 3rd/4th.
5th to 8th: A deep area of low pressure moved north-eastwards across south-west England later on the 5th, to become slow moving across the Midlands and eastern England on the 6th and 7th, before finally moving out into the North Sea on the 8th. This brought periods of heavy and thundery rain during the period to all parts. Flooding reported in south-west England on the 5th and in north-east England on the 6th. High 48-hour rainfall totals in Northumberland on the 5th/6th, with Chillingham Barns recording 158.3 mm and Morpeth Cockle Park recording 151.5 mm, both having return periods over 200 years. As the low moved away on the 8th, most parts had a drier and brighter day, with just a few showers.
9th to 13th: An area of low pressure tracked to the north-west of England on the 9th with a series of weather fronts crossing England, bringing a period of heavy rain. A brief ridge of high pressure on the 10th gave a drier and brighter day. However, more weather fronts crossed the country from the 11th to the 13th bringing more showers or longer spells of rain, which was heavy and thundery in places. Norwich Airport recorded a maximum temperature of 23.4 °C on the 11th. Some notable hourly rainfall totals in Wiltshire on the afternoon of the 12th, with Larkhill recording 28.2 mm and Boscombe Down recording 21.0 mm.
14th to 16th: A ridge of high pressure pushed into eastern England, although weather fronts remained slow moving over the west. This brought cloudy and wet weather to the west, although the east was mainly dry with some sunny spells. It was cool overnight here though with patchy fog forming.
17th to 21st: High pressure built across the whole of England giving a period of fine weather with some good sunny spells. However, there were also some chilly nights with patchy dense fog forming.
22nd to 24th: High pressure still dominated England's weather, although a weak weather front became slow moving over central and eastern England. This brought cloud and a little rain here, but elsewhere it was dry and brighter. Shap (Cumbria) recorded a minimum temperature of -0.2 °C on the 23rd.
25th to 27th: High pressure gave a period of dry and fine weather with some good sunny spells. However, there were also some cool nights, with patches of dense fog forming which were slow to clear during the mornings.
28th to 30th: The high pressure started to decline with a weak weather front on the 28th bringing cloud and a little rain into northern and central parts, although the south stayed fine. Santon Downham (Norfolk) recorded a minimum temperature of 1.2 °C on the 28th. A brief ridge of high pressure on the 29th gave most parts a fine day, but a series of weather fronts spread eastwards on the 30th. This gave a wet end to the month, with outbreaks of rain, which were heavy and persistent in the north-west.
Wales diary of highlights
Generally unsettled for the first half of the month, then drier and brighter.
1st to 7th: Scattered showers on the 1st gradually merged into longer periods of rain. Further heavy rain fell overnight, then brighter with showers on the 2nd and 3rd, but strong south-westerly winds on the 3rd with a gust of 62 m.p.h. at Aberdaron (Gwynedd) and further heavy and prolonged showers over some southern areas. Further prolonged and heavy showers affected the south on the 4th, but drier in the north. Overnight from the 4th to the 5th a band of heavy rain spread northwards, with some flooding reported. Betws-Y-Coed (Conwy) recorded a 24-hour rainfall total of 58.4 mm on the 5th and Capel Curig (Conwy) recording a four-day total of 143.8 mm between the 3rd and 6th. The 6th was more showery and cyclonic, but still with some heavy bursts of rain. The low centre slowly moved away eastwards late on the 7th to leave a few showers and most places becoming dry with sunny spells.
8th to 14th: Most places were dry and sunny on the 8th with a ridge of high pressure. Cloud increased on the 9th with outbreaks of rain and strong southerly winds. The 10th started drier and brighter, but increasing cloud, wind and outbreaks of rain spread from the west through the afternoon. A mild night on the 10th/11th, with Mumbles Head (near Swansea) recording a minimum temperature of 14.7 °C. Rain cleared to sunny spells and showers on the 11th. Rather cloudy at times on the 12th with some showers. Largely dry, sunny at times and pleasantly warm on the 13th and 14th, but with some mist and fog overnight.
15th to 21st: Rather cloudy with outbreaks of rain in western and central parts on the 15th and 16th with some heavy bursts in central parts on the 16th. Some rain at first on the 17th, but then drier and brighter. Dry with sunny spells on the 18th as a ridge of high pressure developed. High pressure remained in charge through the 19th, 20th and 21st with fine sunny weather, but with some mist overnight. Trawsgoed (Ceredigion) recorded a maximum temperature of 21.3 °C on the 20th.
22nd to 30th: Cloud increased on the 22nd, with a weak weather front bringing some outbreaks of light rain. The 23rd to 27th was a mainly dry period with some sunny spells, although there was some mist and fog overnight during this period. Trawsgoed (Ceredigion) recorded a maximum temperature of 19.9 °C on the 26th and Hawarden Airport (Flintshire) recorded a maximum temperature of 19.9 °C on the 27th. Sennybridge recorded a minimum temperature of 0.7 °C on the 27th and 0.6 °C on the 28th. On the 28th, cloud increased with a weak weather front spreading southwards giving some light rain in the north. Rain cleared on the 29th to leave some sunny spells, but then further heavy rain on the 30th. Capel Curig recorded a 24-hour rainfall total of 37.8 mm on the 30th.
Scotland diary of highlights
Generally dull and exceptionally so in the south-west. Rather dry in the north, but wet in the south-east.
1st to 5th: The 1st to the 4th were bright with a mixture of sunshine and showers, some of the showers heavy and prolonged with hail and thunder. Tulloch Bridge (Highland) recorded a minimum temperature of -0.3 °C on the 5th. The rest of the day was mainly dry in the north and west, but rain spread to the south-east, bringing a 24-hour rainfall total of 35.4 mm to Carterhouse (Scottish Borders) on the 5th.
6th to 18th: The south-east stayed wet on the 6th and 7th, with Carterhouse recording another 24-hour rainfall total of 58.1 mm on the 6th, with some local flooding. The north and west stayed mainly dry on the 6th and 7th. The 8th was mainly dry and bright but with scattered and sometimes heavy showers in the afternoon and evening. Many northern areas started bright on the 9th before rain spread north, heavy in places. The south-west brightened later. Showers cleared early on the 10th but cloud and rain then extended north-east to most places later. Rain cleared from eastern Scotland early on the 11th, then brighter conditions with the temperature reaching 21.5 °C at Kinlochewe (Highland). A few showers developed during the 12th, before more general rain spread in from the east during the evening. Remaining rather cloudy on the 13th with some light rain, which cleared from the west later. The 14th was mostly cloudy with patchy rain, turning heavier in the south-west later. The 15th and 16th were cloudy and wet, the rain heavy at times in the west and south-west. The 17th was mainly dry. Rain developed across the north-west through the 18th and spread south-eastwards.
19th to 26th: The 19th and 20th were mainly dry, apart from a little drizzle in the south and west. The best of the sunshine was found in the north-east with Fyvie Castle (Aberdeenshire) reaching 21.9 °C on the 20th. Many parts were dry and bright on the 21st, although light rain gradually pushed in from the north-west. After a touch of frost in Aberdeenshire and the north Highlands, the 22nd was mainly dry with sunny spells. Tulloch Bridge recorded a minimum temperature of -2.1 °C on the 22nd. The best sun on the 23rd was in the far south-west. Elsewhere cloud increased and patchy drizzle developed in the east. This continued into the 24th but died out later. Most areas were cloudy but some sunny spells developed in places. The 25th was rather cloudy, although central and eastern areas saw some sunny spells, with patchy light rain reaching the far north-west later. The 26th was mostly fine but rain and strong winds reached the north during the evening.
27th to 30th: A band of mainly light rain spread south-east on the 27th followed by clearer weather with scattered showers. The 28th and 29th had sunshine and showers, the showers heaviest in the north and west, with it also being quite windy on the 29th. Southern areas became wet overnight and into the 30th. Sunshine and showers in the north, spreading south later. A cool end to the month with maximum temperatures around 11°C in the north and 14°C in the south.
Northern Ireland diary of highlights
A wet first half to the month, but much drier through the second half.
1st to 5th: The 1st to the 3rd saw a mix of sunny spells and showers, some of the showers were heavy and thundery at times, causing localised flooding in Belfast on the 2nd. Sunny intervals and light showers on the 4th. Mainly dry with bright spells on the 5th but rain spread up from the south later, heavy at times and causing localised flooding. Stormont Castle (County Down) recorded a 24-hour rainfall total of 43.1 mm on the 5th.
6th to 18th: Rain cleared east early on the 6th, with fine and dry weather then following until the 8th. The 9th was cloudy with rain, heavy at times. The 10th started mainly dry, but it then became cloudy with rain, which was heavy in places. The 11th started mainly dry and bright, then showery rain, some heavy, spread eastwards. A misty start on the 12th, but then brightening to sunshine and showers. The 13th was dry with some sunshine, with the temperature reaching 20.7 °C at Killowen (County Down). The 14th started dry and bright in the east, but outbreaks of rain spread to all parts during the day. On the 15th, rain in the east cleared during the morning to leave a mainly dry and cloudy day. There was some patchy rain early on the 16th otherwise it was dry, though cloudy, with similar conditions on the 17th. Rain developed and become widespread on the 18th, easing later.
19th to 26th: The 19th and 20th were mainly dry, although it was rather cloudy on the 20th before becoming sunnier on the 20th. The 21st started sunny, then cloud and light rain spread east later. Killowen recorded a maximum temperature of 21.2 °C on the 21st. After chilly nights, the 22nd and 23rd were dry with sunny spells. Derrygonnelly (County Fermanagh) recorded a minimum temperature of 0.3 °C on the 23rd. The 24th and 25th were cloudier but still with some sunshine at times. Any early mist and fog patches cleared after dawn on the 26th to leave a fine day with some sunshine and light southerly winds.
27th to 30th: A band of light rain spread south-east on the 27th otherwise it was dry and bright. The 28th had sunny spells and scattered showers. The 29th was mostly cloudy with scattered showers, although more general rain reached the west later. After a wet night and morning, the rain cleared south-east on the 30th with sunshine and heavy showers following. Ballypatrick Forest (County Antrim) recorded a 24-hour rainfall total of 30.4 mm of rain on the 30th.