St Swithin's Day weather myth bodes badly for rest of summer
Britain is in for a damp and grey summer if the legend of St Swithin's Day is to be believed.
The weather myth states that if it rains on July 15, wet weather will persist for 40 days and 40 nights.
Heavy rain is forecast for the north of the country on Friday, while further south will be cloudy but largely dry, the Met Office said.
Meteorologist Emma Sharples said: "It's different north to south tomorrow - most places have been fine today but we have got a weather system that is going to move into the north of the UK."
She said wet weather will hit Northern Ireland, western Scotland and northern England early in the morning, while further south will be cloudy but with patchy rain.
"The Midlands southwards should really stay dry throughout tomorrow but it will be becoming an increasingly cloudy picture there. The best of any brightness is going to be in the south east.
"If you believe the saying, 40 days and 40 nights of rain in the north to come, and 40 days of staying dry in the south but I think we know that's probably not going to come true."
St Swithin was an Anglo-Saxon bishop of Winchester, who died in AD862. When he was made a saint in 971, his body was dug up and moved to an indoor shrine in the city's cathedral.
Some writers claimed this outraged the heavens, causing rain to pour on the church and continue uninterrupted for 40 days.
But the Met Office said there had not been a record of 40 dry or 40 wet days following St Swithin's Day since records began in 1861.