Crepuscular rays are the dramatic shafts of sunlight that seem to fan out across the sky when a low sun shines through gaps in cloud or below the horizon. The beams become visible because dust and moisture in the air scatter the light back to your eye, while the shadowed lanes between them stay dark. They are at their best in the hazy air of late afternoon and around sunrise.
Worth knowing
Although they seem to splay outward from the sun, crepuscular rays are very nearly parallel — they only appear to fan out because of perspective, the same trick that makes railway tracks seem to meet in the distance.
Note
Still unsure it's the same cloud? Our app, Cloud Point— on iOS and Android — reads a photo and returns the likely type with altitude, useful when a formation is fading faster than you can look it up.
