I saw the biggest rainbow I'd ever seen on Wednesday, in the late afternoon or early evening, after some rain. It was really thick, and bright, with lots of stripes, and it was a full rainbow, too (I didn't notice it being a double rainbow, though, although, I've seen doubles for smaller, thinner ones).
Location: SW Idaho, USA
USDA hardiness zone: 6
Elevation: 2,260 feet Profile post