what is the literacy term called when the mood of a novel matches the weather?

Isn't it sunny?

You might try this literary terms website:
http://web.cn.edu/kwheeler/lit_terms_M.html

Scroll down until you reach MOOD.

=)

It's called "pathetic fallacy," and it was coined by John Ruskin.

The literary term you are referring to is called "pathetic fallacy." Pathetic fallacy is a figure of speech in which human emotions or characteristics are attributed to inanimate objects or abstract ideas, such as when the mood of a novel is said to match the weather. In this case, if the mood of the novel is sunny, it means that the weather within the story is reflective of the positive emotions or cheerful atmosphere of the characters or plot.

To find this answer, one approach is to search for a reputable literary terms website. In this case, the website mentioned is a good resource as it provides a comprehensive list of literary terms and their explanations. By scrolling down to the letter "M" and clicking on the term "Mood," you will be able to find the definition of pathetic fallacy. This website can serve as a valuable tool for further exploration of literary terms and their meanings.