Wet Start to Summer

It's been a wet summer so far, there can be no dispute about that. With two exceptional periods of heavy rain falling, affecting the north of England in June and across parts of central southern England more recently on the 19th-21st July.

The three month period from May-July will have been the wettest recorded in England since reliable rainfall records begun in around 1720. What are the precedents for the late summer after this?

The three worst summers recorded as a whole were probably 1907, 1954 and 1956 in the last century. These were rated as the worst in Manchester in that period, using a specially constructed 'summer index'. However in terms of poor Julies, the period from 1936-1940 was probably one of the worst periods in the last century. July 1936 was the wettest of the century over England and Wales with some areas seeing 300% of the average. Locally for example, we saw 57mm of rain in just 80 minutes here in Eastbourne. 1937 was also dull and wet; in particular Waltham on theWolds (Leics) saw 145mm in a 24 hour period. 1940 was also another cool wet month and in fact the wettest of the century across Scotland.

The period from 1954 to 1958 saw another run of poor Julies, that were cold, dull, and wet. 1956 saw the wettest July in London since records begun with 98mm of rain in less than 2 hours at Staines on the 18-19th. Both 1957 and 1958 were dull and wet with some localised flooding.

More recently, 1988 was dull and cold, remarkably the temperature did not exceed 21C in many places of the south during the whole month. 1993 was also unsettled and cool when the highest temperature of the year was just 29.7C at East Bergholt (Suffolk); the only occasion since 1981 when the annual maximum failed to exceed 30C.

So what happened in the above years during August?  Did the wet dull weather continue?

Well August 1936 and 1937 were actually dry, warm and sunny with the Azores high able to ridge up across the UK. August 1940 was also very dry with virtually no rain, as an anticyclone took up residence across the UK. August's in 1956-1958 remained cold and wet however for many whilst August 1988 was also an unsettled one. 1993 was generally dry and quite sunny but it was cool.

Generally we need a significant pattern change to see a transformation in the weather during late summer and the reality is this is a relatively rare event. For example, there have been only two occasions in the past fifty years when a very warm July has not been followed by an equally good August; likewise an unsettled summer generally 'sets in' by the first two months as strong Atlantic 'jets' of winds push east high above, creating the kind of conditions ripe for a continual chain of depressions to develop. Sadly, there is every indication that will also be the way this year, with further heavy rain events on the cards before the summer is over.