Was September in Marlborough a wet month? Yes, it was - very wet - and here's the proof

Written by Eric Gilbert on .


The beech trees of Savernake Forest (photo: Eric Gilbert) The beech trees of Savernake Forest (photo: Eric Gilbert) If you got the impression that September was a wet month, you were correct. The statistics prove it was a very wet month with total rainfall amounting to 75.0mm, which was 13.5mm above the 33-year average and the wettest September since 2008. The maximum fall was 8.7mm on September 24.


There were in all 17 days classed as wet days - with the rainfall equal to or greater than 1mm - including as many as seven days with modest totals from five to seven millimeters.

Looking more closely into the data I find that we only had six dry days when the average number for dry September days since my station started in 1984, is 16.  What a contrast with the 26 dry days in September 2003.

Not only was it a damp month but - not surprisingly - a cool month, due to the above average cloud cover.  The mean temperature was 0.6C below the 33-year average.  

To analyse the data a little further, the average maximum and minimum were 0.7C and 0.4C respectively below the long-term average.  Only five days were above the average temperature.

There was a warm spell at the beginning of the month with a peak of 22.0C on September 4.  In contrast were the very cool nights at the later end of the month with the coldest night on September 22 with a minimum of 2.2C - giving a brief grass frost.

Much of the blame for this disappointing start to autumn can be blamed on a number of passing low-pressure systems.  The average barometric pressure for September was 3mb below the long-term average.

There was a particularly wet and windy period in the middle of the second week with strong winds gusting to 39mph on September 12.  The exact opposite occurred on September 25 being a very calm day with little wind and a maximum gust of just 8mph.

Fog was evident on five mornings with visibility down to 200m on September 26 and mist prevalent after dawn on four days at the end of the month.

Sunshine during September amounted to 115 hours varying from 9.22 hours on September 1 to no sunshine at all on September 3 and 25.

The changing colours of Autumn are especially evident in Savernake's Forest's beech trees.  A sight that Percy Shelley (1792-1822) would have relished: "In the garden, Autumn is indeed the crowning glory of the year, bringing us fruition of months of thought and care and toil.  And at no season, except perhaps in Daffodil time, do we get such superb effects as from August to November.”