Ask the meteorologist: Can you have a rainbow without rain?🌈

Question: I saw what appeared to be a rainbow, but there had been no recent rain. Also the colors were very vivid and wide and no arch. — Patsy Yates

Answer: You can't have an actual rainbow without rain, and it doesn't seem like you saw a "sun dog." (Those occur when the sun is low in the sky, early or late in the day.)

Ask the meteorologist: What is that ring around the sun?

We're left with thinking you probably saw a circumhorizon arc, which requires the sun to be quite high in the sky. (In fact it only gets that high in our part of the world from around late March to mid-September).

Your description – relatively little curvature and very bright, pure colors – fits that of a circumhorizon arc.

You can see how they form at different times of year at different latitudes, along with a nice gallery of photos, at www.atoptics.co.uk/halo/chafreq.htm. Perhaps the photos there will confirm for you whether this is the phenomenon that you encountered.