Understanding Weather Lore

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 nae mare

Saint Swithun was an Anglo-Saxon bishop of Winchester who, since his death, became most famous for being a weather saint and for the British weather lore proverb which dictates that if it rains on his feast day (July 15th), it will rain for the next 40 days.

At his request, St. Swithun’s body was buried outside when he died in 862, ubi et pedibus praetereuntium et stillicidiis ex alto rorantibus esset obnoxius [where it might be subject to the feet of passers-by and to the raindrops pouring from on high]. However, over a century later on 15th July 971, his body was moved inside the church where a shrine was constructed, dedicated to him. Many miracles are believed to have happened following the move and this day became his feast day. However, on the day of the transition, it rained ferociously, and this continued for 40 days and 40 nights. It is told that the storms were a sign of the saint’s displeasure at his body being moved against his wishes of a humble burial. To this day, it is a tradition to anticipate the weather on 15th July, as legend says that the weather on that day dictates the weather for the 40 days following.

It has been the wish of humans for millennia to be able to accurately predict the weather, and history is full of rhymes and anecdotes when it comes to weather lore. People whose work and living depend on good weather, such as farmers and mariners, have been looking for signs for millennia and, though it is still hard to accurately forecast the weather 100% of the time, even with modern technology, there are still some rhymes that often prove true;

"Red sky at night, shepherd's delight; red sky in the morning, shepherd's warning"

Red skies are the result of the sun shining on the underside of clouds at either sunrise or sunset. At both of these times, the sun’s light passes through The Belt of Venus at a very low angle. Deep red sunsets are associated with dry, calm weather and can indicate an extended spell of good weather, hence the “shepherd’s delight.” Red skies in the morning however, indicate that rain is on its way, hence the “shepherd’s warning”.

A similar saying is “Evening red and morning grey, two sure signs of one fine day”.

“When halo rings the moon or sun, rain's approaching on the run.”

A halo around the sun (solar halo) or moon (luna corona) is a good indicator that the weather is soon going to change, usually leaning towards more wet weather. The halo is caused by ice crystals at high altitude which refract the light of the sun or moon.
 
“When windows won't open, and the salt clogs the shaker, The weather will favour the umbrella maker!”

Windows and doors with wooden frames swell when there is moisture in the air, just as salt absorbs the moisture and clumps together. It is common for both of these things to happen in the humid conditions that often precede thunderstorms.

“A cow with its tail to the West makes the weather best, A cow with its tail to the East makes the weather least”

The direction in which a cow is facing is often a good indicator of weather to come. Cows stand with their backs to the wind, so if a cow is facing the east, it means the weather will continue to be fair, whereas a cow facing the west suggests that the weather will soon be unsettled.

“Seagull, seagull sit on the sand, It's never good weather when you're on land.” 

Seagulls are naturally at home when they are in flight and prefer to sleep on water. When the weather is bad and the wind is making the water choppy, the seagulls tend to huddle on land. This is less a prediction that the weather will be bad than a sign that the wind is already turbulent. Another popular rhyme for this is “When sea birds fly to land there truly is a storm at hand.”

“A coming storm your shooting corns presage, And aches will throb, your hollow tooth will rage.”

Many people complain of tooth ache during a change in weather, as well as an increase in arthritic symptoms. When a storm is approaching, joint fluid levels in the body lessen, just as the fluid in a barometer decreases. This causes the body’s tissues to readjust and expand to fill the space which in turn produces swelling and increased pain.

So the next time you feel an unusual ache or pain, check the sky for red clouds or a solar halo, or if you’re near a field, look out for the direction the cows are facing; your body could be warning you of incoming stormy weather.