These 'rainbow clouds' are called iridescent clouds, and I was very fortunate to spot these while out a couple of weeks back now. They are by far, my favourite weather phenomena to spot, and they always leave me smiling. I've only seen this one other time since moving to the Lake District, so these photos are quite special to me. This happens when tiny water or ice particles in the atmosphere cause light to scatter, though I can't be sure that this isn't also a Sun Dog, another similar weather phenomena, which usually presents itself as a large beam of light with two refracted rainbow like clouds on either side, but I just love the streak of rainbow that appeared in this one cloud and it definitely made me smile on a gloomy week.
I'm linking up with Sue for (Almost) Wordless Wednesday.
Hope you've all had a good day so far!