The averaging period used for the following assessment was 1961-1990.
Scotland, England and Wales experienced average temperatures, with cooler days counteracting the warmer nights. Northern Ireland experienced the best of the weather, with above average temperatures and sunshine, and only around 50 % of its normal September rainfall.
Kinloss experienced its dullest September since records began in 1951, with only 59 hours of sun.
England and Wales diary of highlights
Generally unsettled. Wet spells alternated with quieter, drier interludes. Drier and sunnier in the south-west . Very wet in eastern England and East Anglia.
1st to 5th After a mainly dry start it became rather cool, wet and unsettled with bands of rain or showers crossing the region from the west or north-west. Some of the showers were heavy and thundery at times especially in the north and east. Some sheltered places along the English Channel coast were rather warm at first, Southampton and Torquay reaching 23 °C.
6th to 11th Changeable and mainly dry weather prevailed over the region sandwiched between a complex area of low pressure over Scandinavia and high pressure to the south-west of Ireland. The fresh north-westerly airstream from the Iceland region brought good sunny periods, with southern counties benefiting the most. Southsea reached 23.1 °C on the 7th. Any light rain or showers were confined to northern and eastern counties.
12th to 13th Very wet and windy as a deep low near Iceland moved southeast to the southern North Sea. Buxton in Derbyshire only reached 11 °C on the 13th.
14th to 16th Mostly rather cool and changeable, with good sunny periods, especially in the south. North-eastern areas and East Anglia saw some showers from time to time.
17th to 19th Unsettled with heavy rain at times, particularly in eastern areas, East Anglia and south-east England, as a depression moved south-westwards from Denmark. Gusts over 40 knots were experienced near the Wash.
20th to 22nd A quieter period ensued, allowing some local mist and fog patches to form overnight. It was mostly rather cool with some isolated light rain or showers. Western areas were warmer, sunnier and drier.
23rd to 25th More wet and unsettled weather over northern and eastern areas including the Midlands and East Anglia. Fairly widespread rain and showers, some heavy with thunder, broke out. Showers affected southern areas later. Many places had mist and fog patches which were slow to clear on occasions.
26th to 30th After a dry start, a deepening complex low pressure system west of Ireland brought increasing spells of rain and showers to many parts, the showers becoming heavy and thundery in places later. However it was mostly warm with London touching 24 °C on the 28th. A gust of 63 knots was recorded at Aberdaron (Lleyn Peninsula) during the 30th.
Scotland diary of highlights
North-westerly winds in first half of month followed by settled spell.
The first half of September was generally cool and showery, with north-westerly winds predominating. The second half of the month contained a long spell of settled weather, with a period of easterly winds. The last few days saw deep Atlantic depressions pushing bands of wind and rain north across the country.
From the 1st to the 15th a long spell of north-westerly winds brought changeable and rather cool weather. Fronts pushed bands of rain across the country on the 1st, 6th/7th, 10th, 12th and 14th. Lochcarron and Dalmally recorded 31 mm and 40 mm of rain on the 7th and 12th respectively. A milder interlude on the 11th enabled the temperature at Strathallan to reach 21 °C. Generally, however, bright, showery and cool conditions predominated.
From the 16th to the 26th high pressure was never far way, first of all to the west and then to the north. During the first five days of this period south-western districts enjoyed plenty of sun, while northern and eastern districts were affected by cloud and some bands of rain. For the remainder of the quiet spell of weather there was a good deal of cloud in many parts, but the north and north-west enjoyed sunny periods on some days.
During the last four days of September a deep Atlantic depression pushed fronts north across Scotland, accompanied by spells of wind and rain. The heaviest rain occurred on the night of the 30th, with 41 mm being recorded at Eskdalemuir.
Northern Ireland diary of highlights
Dry, warm and sunny.
1st to 7th Warm but unsettled with showery conditions. Very sunny on 4th but dull on 5th.
8th to 11th Dry but cooler. Conditions particularly dull on 10th and turning warmer by 11th.
12th to 16th Unsettled with scattered showers and sunny spells.
17th to 23rd Dry and sunny at first but turning cooler and duller on 21st and 22nd.
24th to 30th Cool with only scattered showers at first but turning warmer and wetter by 27th. Particularly wet in some parts on 28th and 30th, with thunder in western parts on 29th.