What was this solar phenomenon

We paid a visit to some local tidepools this weekend and the weather was cool with a thin but uninterrupted layer of cloud cover. It was about 3 or 4 in the afternoon, so the sun was past it’s peak, but not quite setting. When we looked at it we could see a circular “rainbow” surrounding the sun. It was about 10 times the diameter of the sun’s disc and had faint bands of color.

Is there a name for this?

Sounds like a halo.

Hmmm. Interesting. It looked exactly like the ice-bow pictures, but we’re in San Diego and it was 60 degrees. Looks like that was it, though.

Just because it’s warm down on the surface of the earth, doesn’t mean there can’t be ice crystals in the upper atmosphere.

True. It also says in Anne Neville’s link that it could be other forms of moisture.

Those cirrus clouds that produce halos are very high in the atmosphere. I’ve seen them above me from an airplane flying at 35,000 feet or so. That high in the atmosphere, it’s always cold enough for ice crystals to form, everywhere in the world.