Can you wear white sandle pumps to a September 22 wedding in Michigan?

Yes. So long as the weather is appropriate and they go with your outfit.

Yes, you can wear white sandal pumps in September in Michigan if the weather is warm. The white shoe after Labor Day rule is no longer valid. The rule is now what is appropriate for the setting and the weather.:)

If your concern is wearing white to a wedding, that usually doesn't apply to shoes. Don't wear a big white dress (or a little one for that matter!) and you won't offend the bride unless she is bridezilla. Some brides don't care if their guests wear white dresses/outfits; I went to a wedding last summer where of the appx. 100 guests AT LEAST 15 were wearing white. The bride didn't seem to notice or care! Then again, I remember hearing about a celebrity wedding (don't remember who) who gave all the guests matching white outfits to wear so everyone would look the same...

Whatever makes you comfortable!
(I'm from MI--September has lots of good weather days!)