N'étendez jamais votre linge de couleur un soir de pleine lune. En effet, ces nuits sont plus froides que les autres et font poindre une rosée contenant du peroxyde d'hydrogène, composant qui décolore le linge.
Never put your clothes to dry on a full moon night. Indeed, these nights are colder than others, and trigger a dew containing hydrogen peroxide, a substance that removes clothes' color.
My grandmother used to tell me the same thing. Should I obey her?
July: Two full moons in this month (1st and
31st). 17 nights were colder than the coldest full moon night.
August: 3 nights were colder
Sept: 3 nights were colder
Oct: 3 nights were colder
Nov:3 nights were colder
Dec. 18 nights were colder
There are ways (other than monthly) that the data can be grouped. Here is a summary of the 7 days before and after each full moon:
Jan 4: 71% were colder than full moon
Feb. 3: 14% were colder than full moon
Mar 5: 57% were colder than full moon
Apr 4: 21% were colder than full moon
May 3: 35% were colder than full moon
June 2: 14% were colder than full moon
July 1: 78% were colder than full moon
July 31: 85% were colder than full moon
Aug 29: 14% were colder than full moon
Sep 27: 50% were colder than full moon
Oct 27: 0% were colder than full moon
Nov 25: 21% were colder than full moon
Dec 25: 64% were colder than full moon
I didn't run a statistical analysis to look for the amount of correlation between phase of the moon and temperature, but as a absolute rule (full moon is always colder [than nights without full moon] there are numerous counter-examples to show that is false. As a general rule (that may have exceptions) . . .well, there are LOTS of exceptions.
For the 2nd claim, that the amount of hydrogen peroxide produced in dew increases with decreasing temperature: Even if it is true, you would need to evaluate the risk to your laundry using exactly that: Temperature (not phase of the moon).