Why does it always rain on me?

Is red sky at night really a shepherd’s delight? If cows are sitting down, will it rain? These questions and more are tackled in The Secret World of Weather by Tristan Gooley.

Brits love to chat about it, it affects everyone, can be unsafe and destructive, but very few people pay attention to it. Taking an active interest in the weather and understanding it is essential for outdoor swimming – but when you are advised to check the conditions, do you actually know what that means?

Tristan Gooley’s book, The Secret World of Weather, is essential reading for outdoor swimmers. Not only does it tackle simple weather systems and signs that happen every day, but it can also help you predict changing conditions and teach you skills that will enhance your time outdoors – whether you are in an urban environment, at the beach or more remote.

Can you predict a rain shower?

“The weather forecast these days tends to be good at big broad sweeps,” says Tristan. “You will understand a weather front and when there is a massive change coming, forecasters generally don’t get this sort of thing wrong. But what is less understood is the world of showers and everything that goes with it. Most people, I imagine, swim mostly in the summer months, which is when the UK is vulnerable to showers. Having a few raindrops on your head doesn’t do any harm, as a swimmer you will be wet anyway, but it does change the experience and can actually be quite scary. If you are more than a few metres away from the edge of whatever water you are in, the sky suddenly goes black, you get heavy rain and potentially even lightening, that is an entirely different world.”

Known famously as the ‘natural navigator’, Tristan books are bestsellers. They are brilliant guides to the outdoors and offer tips, tricks and skills to understand our wild world. Like all his books, once you learn and understand the natural signs and rules he explains, it will change your experience with the outdoors and perhaps even make you a safer swimmer.

“I don’t think many people understand showers at all,” says Tristan. “The sun heats the ground, but doesn’t do it in a uniform way – some areas heat up more than others and water is one of the last things to heat up, which means there will be patches of land up-wind of where you are swimming that may get particularly warm and may create some spicy showers, even storms. There is more detail about this in the book, but just being able to notice when the clouds are taller and why, can be powerful.”

Why understanding the wind is important to swimmers

As well as understanding showers, Tristan also recommends swimmers understand wind. Wherever we get our weather forecast, a news website or the Met Office, they will give us a general picture, which is very general when you consider the surface of the earth. “Whether you are walking or swimming, it is the same deal,” says Tristan.

“If you look at a forecast it might say the wind is blowing from the west at 10 miles an hour. That will be really quite accurate 50 feet above your head, but in terms of your experience in the water, the forecast isn’t going to be relevant. It won’t tally with your experience closely at all, because when the wind comes into contact with the ground all sorts of interesting things are happening. It accelerates through gaps; it gets tripped up by trees and buildings. It is different to the winds you feel and changes the surface of the water. If you are planning on a swim and you know there is a slightly stronger wind forecast, you might plan your swim differently. But when you get to the water’s edge you will find that the wind is not only doing something different to what the forecast said, but several things different to the forecast. So, what I say is that if you plan a 10-minute walk, you should expect to encounter 10 different winds. I would expect the same sort of thing if you were swimming across a lake for 10 minutes, I would expect you to meet 10 different winds during your experience. They will be dictated by the shape of the land and the features on the land.”

Think air temperature, not just water temperature

Another thing that swimmers are often obsessed with is temperature, but we shouldn’t just be focused on the water temperature. Tristan encourages us to understand the air above the water.

“Both the winds and showers will be influenced by the fact that there is a body of cooler air above the water,” he says. “Often this means that if there isn’t a strong wind, you won’t get showers over a massive lake in summer because the air above the water is cool, so it is worth knowing that sometimes heavy showers and storms won’t reach a big lake. The same phenomenon can work at the coast, you can see rain clouds, but it won’t rain until it moves inland over warmer air. Of course, this is just one example and in summer, so it isn’t a safety rule that you will be protected if you are in the water. It can be interesting though and quite common, particularly places like the Lake District. You can often see clouds towering up on the hillsides but if you are walking at the edge of a lake, or even in it, you can see this beautiful hole of blue sky above you because the clouds can’t form over the cold water.”

People who spend more time outdoors generally pay more attention to the weather and the seasons, mainly because it impacts on your chosen outdoor activity. “Whether you are a swimmer, walker or kayaker you will need to pay attention because you will need to pack differently to ensure you have the right equipment or clothes,” says Tristan. “But in general, I would say people take the weather for granted. Over the last year [during the lockdown] people have paid more attention to their local outdoor space and the weather, because they had no other choice. But are often unprepared. So often I might head into central London and I am surprised to see people without an umbrella when the forecast was clear that rain would fall all day.”

“There is a very interesting relationship between time spent outside and the need to get things right. When I was a student in Newcastle, I inherited their way of doing things. For example, for a night out in January, gales and snow, the men are mostly in t-shirts and the women are in even more light clothing and skirts, despite it being minus seven degrees outside. But the logic was that they only planned on being outside for 15 minutes, so would prefer to freeze in the queue for the club for a short time rather than having all this kit they didn’t need for four hours inside. Your relationship with the weather becomes more sensitive the more time you spend outdoors and depending on what you are doing.”

Weather science and weather lore

Tristan’s work is firmly rooted in science but tackles lore. He writes, “If I’d been given a pound for every time I’ve been asked whether cows lying down signal rain, I could have bought a calf.” Sadly, there isn’t any science that backs it up but there are some signs that have proven true.

Red sky in the morning or at night is a great example of how fair or bad weather is predicted based on the fact that the sun sets in the west and rises in the east. Bees and ants are a sign of warmer weather and a spider will spin smaller webs when it is windy. I loved learning about sun pockets and the detail of clouds. When it comes to weather, nothing is random: something caused that cloud to be there. And when you are reading clouds, morning and afternoon are not the same.

The Secret World of Weather is out now. Discover more of Tristan Gooley’s books on his Natural Navigator website.

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