This Monday, the 15th July, is St Swithin’s Day. Isobel Lang looks at whether there is any truth in the saying.

Some of you may well be familiar with the weather lore associated with this day:

St Swithin’s Day, if it does rain
Full forty days, it will remain
St Swithin’s Day, if it be fair
For forty days, t’will rain no more.

Basically this myth states that if it rains on St Swithin’s Day it will rain for the next 40 days, or if it is fine it will be fine for the next 40 days - well, I wish we could all be that certain in our forecasts!

According to the Meteorological Office this is untrue. They have tested the myth on 55 occasions and each time 40 days of similar weather did not follow.

Despite having dismissed this just now as ‘rubbish’ there is quite an interesting story behind the legend.

St Swithin was an Anglo Saxon Bishop of Winchester and legend says that as he lay on his deathbed he asked to be buried in a churchyard "where the rain would fall on him and the feet of ordinary men could pass over him."

His wishes were followed for nine years but then the monks of Winchester decided to move his remains to a shrine in Winchester Cathedral on the 15th July 971. According to the myth there was a massive storm and it rained for 40 days.

Some other tales do have sound meteorological substance, for example:

Red sky at night, shepherd’s delight;
Red sky in the morning, shepherd’s warning.

The sky appears red due to dust particles or dry air. In the UK as weather systems move mostly from west to east, a red sunrise indicates wet weather coming from the west. Conversely, a red sunset hints of dry weather to come from the west.

If there is fog accompanied by wind, expect rain.

When wind and fog occur, the likely cause is the approach of a front - and that implies rain.