#4: A ring around the moon means rain tomorrow
The sight itself is real and useful. A pale circle around the moon often comes from ice crystals in high cirrus or cirrostratus clouds, and those clouds can appear ahead of an approaching weather system. That connection probably helped the old rule survive. Where folklore goes too far is turning “may be approaching” into “rain tomorrow.” A halo can form without rain reaching your location at all, and even when precipitation does follow, the timing is not conveniently locked to the next calendar day.
