Does the full moon have anything to do with our weather? Does the weather change at full moon or at new moon? Is there actually more or less rain and does the temperature therefore drop or rise? A few questions that everyone has surely heard of in one or the other form …
If you ask a meteorologist about the connection between moon cycles and the weather on earth, it is pretty certain, he will answer by saying there is no correlation. Especially the frequently quoted change of weather at full moon or new moon does not take place, because the moon phases pertain as a cosmic event to the entire globe at the same time. If this change of weather should really exist, it would have to occur in all places of the world simultaneously. That this is not the case, can easily be proven based on weather data.
But how did all these weather lores (the name for the folk sayings about the weather) and the belief in the connection between weather and moon events emerge? One may assume that people have observed the weather during the course of centuries, because predictions were valuable, in particular for agricultural work. Notes were taken and correlated with temporal events, i. e. seasons, months, day and night times. And because the moon displays another and clearly visible periodic cycle, it was an obvious choice to observe the weather conjointly with the phases of the moon.
In the age of global meteorology and weather observation, one has to remind oneself that the weather lores are of regional origin and therefore, if effective, only retain its validity if looked at from a regional point of view. Thus evidently, they cannot be globally transferred and are not valid for every place on earth.
Let’s close today with a full moon lore that may not directly target the weather, but brightens up the disposition: »The farmer’s wife milks goats at night, just blame it on the full moon light!«