What are winter rainbows?
I have received many letters about seeing winter rainbows on very cold days. This one is from Mrs. Ethel St. Jean of New Liskeard, ON. Others such as Celine Trifts of Moncton and Bob Admans of Stratford, ON ask about the appearance of rainbows or snowbows in blizzards. If there are no water droplets, there can be no rainbows. In the winter, the sky is filled with brilliantly coloured optical phenomena including haloes, light pillars, arcs, spots, patches, and coloured circles. In winter, these luminous arcs in the sky, and rainbow-tinted halos and sundogs are often confused with rainbows. A rainbow is due to the action on light of water droplets. A halo results from the refraction of sunlight by ice crystals. You will not confuse rainbows with halos if you remember that rainbows are always centred in the sky opposite the sun or other source of light, while halos, except for a few rare varieties, are seen surrounding or otherwise near the source of light whether it be the sun, moon, str
