A balmy celebration: Can we expect a sunny opening ceremony?

Author: Matthew Keep

Samuel Johnson once said that "when two Englishmen meet, their first talk is of the weather", and so that should put the Met Office in a good position to tell us what the weather will be like next week at the opening ceremony of the 2012 Olympic Games. And as Olympic officials and athletes start arriving into London ahead of the Games, the Telegraph reports that the Met Office are hopeful that the "weather forecast may improve in time for Games". Matthew Keep takes a look at the weather in previous London Games in the final part of our continuing series of extracts from the upcoming book, Olympic Britain. Olympic Britain shows through statistics the changing face of Britain since the previous London Olympics of 1908 and 1948.

The British obsession with the weather is no doubt due to its unpredictability, and as the date of the opening ceremony for the 2012 London Olympics approaches, the host nation will begin to worry about what the weather holds for that day, July 27th.

Previous London Olympics’ opening ceremonies offer a characteristically inconsistent insight. The opening ceremony for 1948 was, ‘a perfect day with a blazing sun to welcome the teams and the spectators’, whereas in 1908, ‘there was not much sunshine, but the rain of the morning held off during most of the afternoon’.

English weather statistics offer some of the longest consistent time series in the world. Daily mean temperatures for Central England are available back to 1772 thanks, in the main, to the work of Professor Gordon Manley in the 1950s.

Since 1772 the warmest July 27th was in the Olympic year of 1948 when the mean temperature across the region was 21.9oC. The two coldest July 27ths both happened in the 19th century. Mean temperatures of 10.6oC and 11.0oC were recorded in 1867 and 1823 respectively. Since 1900, July 27th has been the 24th warmest day of the year on average.

While organisers will be hoping for warm weather, they will probably be more concerned that the opening ceremony is not affected by rain (the Olympic stadium is not fully covered). Since 1931, July 27th has been rain free in the South East of England on 38 occasions out of 70, and the average daily rainfall has been 1.4 mm. On average July 27th has been the 48th driest day of the year.

If the opening ceremony is to be the scene of the hottest temperature recorded in the UK, the temperature will have to top that recorded on 10th August 2003 in Kent of 38.5oC. If it is to avoid being the site of the wettest day recorded, it will need to receive less than the 28cm that fell in Dorset on 18 July 1955.

So-called summer. The chart shows the average maximum and minimum temperatures and rainfall recorded across Southern England during each summer since 1910.

This article is taken from Olympic Britain, a forthcoming book from the House of Commons Library. It tells the story of the profound economic and social change in the UK since the two previous London Olympics, in 1908 and 1948, using statistics and expert analysis. It will be published on 9 July and digital copies will be freely available on the Parliament website.