We have a weather lore rhyme that goes:
St. Swithun's day, if thou dost rain,
For forty days it will remain;
St. Swithun's day, if thou be fair,
For forty days 'twill rain na mair.
The myth originates from the time of a Saxon bishop called Swithin. As he lay dying he requested to buried outdoors so that he could be trampled upon and rained upon. However, nine years later - on July 15th - his remains were moved to a shrine inside Winchester Cathedral and during this time there was a violent storm which lasted for forty days. This led to the old wives tale we have above.
Is there any truth in it?
Well, apparently the Met Office have put this to the test on at least 55 occasions when it has rained on St. Swithin's day and they found that forty days of rain did not follow. The fact that the British summer can either be wonderful or miserable is down to weather patterns that set in by the middle of July. Either Atlantic weather systems will fall directly across the UK, bringing wet weather or they will pass to the North, bringing fair and settled weather.
So it would seem St. Swithin has little to do with cursing our summers here in the UK, it is down to mother nature and how a weather system forms during July. That said, we got rain on St. Swithin's day and have experienced rain every day since. This has prompted me to conduct my own survey and I am recording my findings for future reference.