Question:
My grandmother used to look at the moon and say if the temperature would be hot or cold. I think she was referring to the declination of the moon. If it was further north then the weather would be colder. If further south then warmer. I can see how the moon can have tidal effects on the atmosphere, but is there any truth to this folklore? – Jim B.
Answer:
Your grandmother is right that the moon affects Earth’s temperature: at Full Moon, the poles can experience temperatures up to a degree Fahrenheit HIGHER than at New Moon (an average of 0.036 F across the globe). We do know that the Moon helps to keep our climate (long-term weather patterns) more stable than if it didn’t exist where it is – keeping Earth’s seasons fairly stable and predictable (less wobbling of the Earth’s tilt that gives us our seasons).
The lunar tidal effects are more noticeable in the ocean than in the atmosphere, especially with the changes of the moon’s orbital plane shifting in relation to Earth’s equator over a 18.6 year period, greatly affecting how warm water at the ocean surface mixes with the cold water below. Here’s one study that looked into weather folklore in the Mediterranean (rainy vs. dry period forecasted by observing the moon’s “horns” changing – likely due to the Moon’s declination shifts over the 18.6 year period):Â Â https://adsabs.harvard.edu/
