I saw fog bow on May 16, 2016. A fog bow is the same effect as a rainbow but the sunlight is being refracted by fog droplets instead of rain. The result is a bow that is white but of the same angular size as a rainbow.
This fog bow sighting followed a night of star gazing at Palomar Observatory Campground, the first Explore the Stars event for 2016:
Meteor in Delphinius
Milky Way in late spring