On Friday night many residents across Connecticut were in awe of a very large lunar halo. These “rings around the moon” are not uncommon, but this one was large, and also featured a very bright Jupiter just to the upper left of the moon. This halo occurred as light from the moon was shining through a very thin layer of high cirrus clouds. This ice crystals in the clouds disperse light in all directions – hence the perfect circle.

In weather lore, a ring around the moon is often indicative of a change in the weather or “snow in 3 days time.” While this can be true in certain situations, it really just signals that there are high clouds around. The high clouds could be transient, but could also indeed be the leading edge of a larger storm system, set to hit within the next 24-72 hours. Like many aspects of weather lore, there is some truth to the old sayings, but by no means does the “snow in 3 days” occur every time.