Sir, – I would like to add to Patrick Lydon’s comment on statistics and the present Irish summer (August 28th).
How good or bad a summer is can be determined by the amount of rainfall, the temperature and the level of sunshine recorded. In order to allow comparison between summers it is useful to reduce these statistics to a single figure.
A formula that uses qualitative weightings can be applied to the total amount of rainfall, the average temperature (or average maximum temperature) and the total hours of sunshine for the summer months.
One such formula, the Poulter Index, was developed in 1962 and was initially used to rate the summers at the Kew observatory in England. They get a lot less rain in Kew than in Ireland. I expect the Poulter Index value for the present summer will be under 300 for Dublin, which will be considerably below the average of 350 and far below the best summer of 1995, which had an index value of 434 (using Phoenix Park data).
I agree with Mr Lydon that this summer, especially the continued wetness of the ground, is extremely bad. Perhaps Met Éireann could develop an Irish Summer Index formula which might reflect our special relationship with rain. This index could, for example, take into account the number of rain days as well as total rainfall.
Met Éireann can only work with the data collected but I would also agree with Mr Lydon that the use of the term “normal’ in describing the present summer and the “we do not live in the Mediterranean” argument do not convince people. Everyone knows this has been a very bad summer. I think we need our own index to reflect this. – Yours, etc,