THE first six days of September were dry, sunny and warm. This made up a little for our mediocre August and provided a pleasant extension to the summer. Then, things went downhill quickly and the month drew to a close with a notably cool, damp week of autumnal gloom.

The drought, which lasted just seven days, was abruptly ended by torrential rain in the early hours of the 7th. With up to 25mm (1.0in), it was the wettest day of the month in our region except for the east, where the 23rd qualified for this dubious honour.

As far as I’m aware, Carlton, near Stokesley, had the largest total on the latter occasion.

With 36mm (1.4in), well over half the mean for the month, it was my second most sodden September day after the 5th in 2008, when 39mm (1.5in) poured down. Over the month, rainfall accumulations were close to average in the Dales, but there was as much as double the norm in the east. Here, this more than compensated for the shortage registered in the summer. At Carlton, it was my third wettest September in 28 years of data, after those of 1995 (138mm, 5.45in) and 1993 (136mm, 5.35in).

The risk of thunder and hail declines sharply in the autumn as sunshine rapidly weakens and, as a result, the potential intensity of showers.

However, this time, thunder was heard on the 7th and 23rd in many parts of the North-East, as at Carlton, the most here in a September since I observed it on four days back in 2000. Even so, the year is probably going to finish with the fewest number of days with thunder in my logs. Strangely, hail remains completely absent from my September records – the only month with such a deficiency.

High pressure was in control at the start of the month, but soon gave way to Atlantic depressions.

It became very changeable but, with winds blowing mainly from the south to south-west until mid-month, it stayed quite warm. From the 16th, they veered north-westerly. A mild, southerly breeze resumed the following week, but north to north-easterlies replaced them by the final weekend.

Septembers figures at Carlton-in-Cleveland: Mean maximum: 17.5C, 63.5F (+0.4C, 0.7F); mean minimum: 10.1C, 50F (+0.5C, 0.8F); highest maximum: 22.0C, 71.5F, 3rd; lowest minimum: 4.1C, 39.5F, 17th; total rainfall: 111mm, 4.35in (+53mm, 2.05in); wettest day: 36mm, 1.4in, 23rd; number of rain days, with 0.2mm (0.01in) or more: 20 (7).

Figures in brackets show the difference from the 27-year mean, 1983-2009.