Splendid beginning to the New Year of 2020. Amazing appearance of a double rainbow to break up the monotony of the dark overcast and rain. Folks came down to the river for a breath of fresh air and to enjoy the brief sunshine. Then, there it was! Captured by none other than an iPhone.
A rainbow is an optical illusion caused by light passing through water droplets which creates a spectrum of arced light to appear from certain perspectives. There are some technical details but it depends upon the viewer and their location relative to the phenomenon.