Legend has it that if it rains today, it will rain for 40 days and 40 nights, putting an end to the favourable conditions the country has sporadically experienced throughout the summer.
If it remains dry, however, folklore predicts 40 days and nights of nice weather will follow.
Met Éireann predicts today will be mostly dry, though some parts of the country may experience light showers. Highest temperatures are expected to be between 16C and 19C with light and variable winds.
Rainclouds are set to dominate the skylines for the rest of the week, however, with the south and east to receive the lion’s share of the wet weather. Highest temperatures will be between 15C and 18C.
If it does rain today, people are urged to remain calm — there has been no record of 40 days of continuous rain or sunshine following St Swithin’s Day since records began in 1861.
Forecasters are predicting settled weather across the country towards the end of July, with only occasional spells of rain. Plenty of fine, dry weather is also expected in the first half of August again, with a risk of short-lived patches of wet weather.
The earliest reference to the St Swithin’s Day myth dates back to the 14th century. It is believed St Swithin was an Anglo-Saxon bishop in Winchester in the UK. He was said to have performed a miracle when he made eggs whole again after they were broken by workmen building a church.
St Swithin is thought to have died in 862AD and was made a saint 109 years later, when his body was exhumed and moved to an indoor shrine in the city’s cathedral.
Some writers claimed this outraged the heavens, as St Swithin did not appreciate his bones being relocated from their humble resting place, and expressed his anger with 40 days and 40 nights of continuous rain.
The proverb stemming from this occurrence reads: “St Swithun’s day if thou dost rain, For 40 days it will remain. St Swithun’s day if thou be fair, For 40 days ‘twill rain nae mare.”