From Andrew Brightwell
I am sure I have twice seen a rainbow similar to a circumhorizontal arc in England (17 June, p 17). On both occasions it was just before dawn with a high-contrast spectrum rainbow high in the sky between me and the rising sun. The first time, offshore in summer, the sky was clear apart from a few high-altitude wisps of cloud. On the second it appeared through a large gap in the winter clouds. Unlike your photo, my rainbow covered only a few degrees horizontally – nonetheless, it was still spectacular.
Okehampton, Devon, UK
