LONDON (Reuters) - Incessant rain in Britain this summer has washed out festivals, drenched royal pageants and now even threatens to cast a pall over the Olympic Games - but help may be at hand from a higher power.
Old English folklore holds that St Swithin's day, which falls on Sunday, acts as a marker for the following month.
If it rains then, it will pour for the next 40 days. But if the weather is fine, it will stay that way.
And, after the wettest summer since modern records began, the forecast for Sunday is for dry weather.
The Games start in two weeks' time and forecasts suggest that while the bouts of heavy rain may abate, London weather could still be wetter than average for much of the Olympic fortnight.
Fears have been raised that the lavish opening ceremony and athletics sprint events, among others, could be marred by rain in the same way as the Queen's diamond jubilee river pageant was back in May.
St Swithin was a Saxon bishop who died more than 1,100 years ago in 862. He was buried according to his wishes just outside Winchester cathedral in southern England so that people would walk across his grave and the rain would fall on it.
But he was subsequently reburied in a shrine inside the cathedral, an act which was accompanied by violent rainstorms which lasted 40 days and 40 nights and were widely held to be a mark of his displeasure at being moved inside.
The traditional rhyme runs:
"St Swithin's day if thou dost rain
For forty days it will remain,
St Swithin's day if thou be fair
For forty days 'twill rain na mair"
Hoping for a dry 40 days after Sunday may however require a leap of faith.
British weather records over the last 160 years show no evidence of a 40-day St Swithin's pattern.
(Reporting by Zola Hargreaves; Writing by Steve Addison; Editing by Andrew Heavens)