This morning I looked outside, did a double take, and briefly wondered whether I was still half-asleep. Because the fog was pink.

Not sort of pink. Proper, rosy, “has someone messed with the settings?” pink. In all my years of staring out of windows and obsessing about the weather, I don’t think I’ve ever seen that before, so naturally my first thought was: what on earth is going on now?

Thankfully, it turns out nothing dramatic was unfolding and the world hadn’t gone weird overnight. It’s just a neat trick of light. When the sun is low, early morning or late evening, its light has to travel through a lot more atmosphere. The blues get scattered off elsewhere, leaving the warmer reds and pinks behind.

Throw some fog into the mix and it acts like a massive diffuser, spreading that colour everywhere. Instead of grey murk, you get a landscape that looks like it’s been gently dipped in strawberry yoghurt.

That’s why pink fog usually shows up:

• Early in the morning or later in the day
• In winter, when the sun never really gets its act together
• During calm, foggy high-pressure weather

Of course, it didn’t last. The sun climbed a bit higher, the fog thinned, and everything went back to its usual sensible grey. But for a short while this morning, the world looked like it had accidentally put a filter on and I’m very glad I looked out of the window when I did.

It was certainly different.