Why do I see rainbows around the moon? Regularly, I see rainbows around the moon. Here is approximately what I see:



Right at the edge of the moon, I see a bright blue ring of light. Further out, I see an inner rainbow. This is not as bright as the ring, but is still clearly visible. Even further out, I see an outer rainbow that is very faint. 

I see the blue ring during every full moon. I see the rainbows more frequently in late fall and winter than in spring or summer. But every year, I see these moon rainbows during a full moon.

Since I see these moon rainbows more frequently in late fall and in winter, are these moon rainbows caused by moonlight reflecting off of ice crystals in cirrus clouds high up enough that I can't see the clouds? Also, why do I see a bright blue ring right at the edge of the moon during every full moon?
There are a couple of atmospheric phenomena that can create rings around the moon.

Corona are caused by water droplets diffracting the moon's light, they are fairly small, and close to the moon. They are coloured but not as brightly as a rainbow. Our eyes are also not so good at seeing colours in dim light.

The 22-degree halo is a larger ring, as big as two hands stretched out at arms length. Solar halos are clearly coloured, lunar halos are dimmer and I haven't seen lunar halos that are bright enough to appear coloured to me.

An eye condition, astagmatism, can also create rings, such as the "thin blue ring" (though I am not a doctor) You may be seeing a combination of all three at various times.