By Philip Eden

The centrepiece of September�s weather in England and Wales was a nine-day warm spell from the 13th to the 21st during which the temperature regularly reached 27°C or 28�C in southeast England. However, the last week was much cooler with widespread ground frost on several nights, and snow fell over the Scottish highlands. Overall, it was the sunniest September since 1964, but rainfall and mean temperature were very similar to last September�s.

The Central England Temperature (CET) for September 2003 was 14.5°C, which is 0.8 degC above the mean for the standard reference period 1971-2000, the merest fraction above September 2002�s 14.4�C, and slightly below September 2000�s 14.7�C. In the last 100 years, only 15 Septembers were warmer, two had the same mean temperature, and 83 were cooler.

There was, however, a marked contrast between warm days and cool nights. Average afternoon maxima ranged from 0.5-1.0 degC above normal in northern and western Scotland and Northern Ireland, to 3.0-3.5 degC above in parts of southern, central and eastern England. Average night minima ranged from 0.5-1.0 degC above normal in northern, eastern and central Scotland to 0.5-1.0 degC below normal in southeast England and East Anglia.

The temperature exceeded 25�C somewhere in the country daily on the 4th, 5th, and daily from the 13th-21st. A maximum of 28.4�C was recorded at Gravesend on the 17th. The last week was much cooler, and on the 23rd the maximum was just 8.5�C at Lerwick and Aviemore. Widespread ground frost and local air frost occurred on several nights towards the end of the month, and the minimum of -3.5�C in Strathardle, Perthshire, early on the 24th was the lowest anywhere in the UK in September since 1993. In southern England several places recorded an air frost that night, and locally in Berkshire it was the coldest September night since 1919.

Rainfall, averaged over England and Wales, was 38mm which is 47 per cent of the average for the standard reference period 1971-2000. During the last 100 years only 14 Septembers were drier while 86 were wetter. In the main population centres in Scotland the total for September 2003 was 58mm which is 81 per cent of the normal amount, and the Northern Ireland total of 66mm was also 81 per cent of normal.

Monthly rainfall totals ranged from just 3.3mm at Bognor Regis is Sussex to 192mm at Capel Curig in Snowdonia. Percentages ranged from 5% at Bognor to 150% at Rhyl in northeast Wales.

Sunshine over England and Wales totalled 183 hours during September 2003 which is 129 per cent of the long-term average for the month. Only the Septembers of 1964 and 1959 were sunnier in the last 50 years. The equivalent figure for Scotland's main population centres was 130 hours (113 per cent), and for Northern Ireland it was 111 hours (91 per cent). Monthly aggregates ranged from 84 hours at Stornoway in the Western Isles to 255 hours at Manston in east Kent. Percentages ranged from 75 at Londonderry to 155 at Margate in Kent.

(c) Philip Eden