How I mastered the art of cloud-reading—and learned to see the future

Living on a low-lying island—a place of wide-open vistas—I have become increasingly aware of the shifting patterns of the clouds in the sky and how they relate to the weather.

From a field near my house, one might stand and watch a curtain of rain drawing across mainland Scotland then advancing across the waters of the Pentland Firth. As it approaches, it obscures first the high hills of Hoy and then the smooth green back of Graemsay, which rises like a whale from the waters of the sound. Then the air begins to shift; a susurrus rises from the dry grasses, and my hair lifts from my face. It’s not long before the wind is so strong that it’s sucking the breath from my lungs. With a long view like this, I can see wind for what it really is: vast currents of air rushing from a region of high pressure to one of low pressure. I grasp the true meaning of the term “weather system,” in all its gargantuan scale, for the first time.

When I lived in the city, weather often seemed incidental: a kaleidoscopic backdrop that unfolded behind window panes and in the gaps between the buildings. But here on the island—and especially while we are not able to visit our friends in their homes—the weather has become one of the most significant factors in how each day will unfold. So I have begun to pay more attention to the drama unfolding in the sky, and learning to read the sky for what it might tell me about the future. For there are a number of telling phenomena that might help us plan our days—if only we can learn to appreciate them.

Some are fairly easy to get a handle on. Rainbows, for example, we all know to be associated with sunny spells in rainy days. But timing is significant. Morning rainbows usually indicate rainclouds approaching from the west, while evening rainbows tend to be callbacks to rain that has been and gone, now wafting off across the North Sea. Their appearance, too, tell us of the nature of the rain. A very bright bow, with a vibrant red rim, indicates heavy drops; the paler the colours, the lighter the rainfall. (A thin mist or haar might produce a pure white “fog bow,” with a spectral beauty all its own.)

Failing that, the clouds themselves offer insight, if you take the time to decode them. For example: the expert outdoorsman Tristan Gooley suggests standing with your back to the wind, then checking whether the highest clouds are moving in a different direction to those lower down. If the uppermost layer is moving from left to right, it usually indicates an advancing warm front—and rain. (I highly recommend Gooley’s books, treasure troves of natural trivia.)

Think of clouds as the original sky writing. A snapshot tells you little—it’s all to do with the patterns in which they appear. You need to watch them unfold. High-level formations like wispy cirrus clouds might indicate the approach of a warm front. Brace for rain if they are followed over the next few hours either by cirrostratus (a high, thin sheet that often throws a luminous halo around the sun) or by altostratus clouds, which are thicker, and hover in the mid-levels.

Altostratus clouds bring light precipitation, but they too can morph into nimbostratus clouds—our nemeses here, on this very wet island—a huge, spreading cloud type that spells continuous rain, snow or sleet. The Met Office describes them as “probably the least picturesque of all the main cloud types.” This I can confirm, as I am reporting to you from the middle of one now. It’s been raining for what feels like days. At least I can truthfully say: I saw it coming.