A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2019 Sep 17, 12:17 -0700
The crappy "Farmers' Almanac" may refer to it as folklore, but this is one of those phenomena that is well-grounded in meteorological science. A 22° halo (the only big halo you'll see) around the Moon is created by ice crystals in high cirrus clouds. And high cirrus clouds usually precede a front. And fronts are normally accompanied by rain or snow. A "ring around the Moon" in winter is a reliable predictor of snow.