Cloudspotters tend to think of the altostratus as a boring cloud. Indeed, it is a featureless, mid-level layer, which tends to give the sky a washed-out, overcast appearance. When it is thick, it is little more than a grey blanket that leads to prolonged light rain or snow. Much of the time, there seems little to recommend the altostratus.

But every cloud has its day – or rather, its time of day – and for this cloud, it is at sunrise and sunset. As you can see from the beautiful example above, that is when the altostratus dons her fancy clothes to paint the sky red. Her gentle undulations become visible for all to admire, her delicate surface awash with ruby hues.

She may be plain by day but, for fleeting moments at dawn and day’s end, the altostratus has a beauty to match any one of her more flamboyant cloud cousins.