There is a graphic which shows average levels of rainfall in Marley. The most rainfalled month is September. September has over 80 rainfalls, probably beacause this is an begining of fall. Than November and October has also a lot of rainfallls. But lower than September itself. Overall fall months are clearly the most rainfalled
January and December are in second and third places respectivaly. This is the peak of winter, when snow falls a lot. However February is one the lowest rainfalled month. More likely the reason is the end of winter. In February snow smelting slowly and no more falling.
Spring months are stable, all beacause nature are blossoming, and rain rarely rains. June and July has also approximately same indicator as spring months. So no wonder, it is beacause summer is one of the hotest season, and there is almost no rain or others rainfalls.
As the Result September is the most rainfalled month and May is the lowest one. There is no anomalises and other problems.