This type of Sonnet is not a Shakespearean one. I think this piece would benefit more if it had a note as to what type of sonnet this is.
I like the use of seasons and I see the relationship of the title with the content.
What I liked the most was the last line as it is really true, December brings a new phase to souls. I thought each month symbolizes something for the author but at times I thought it was just in general. I would have like it more if it was more uniform in the sense that either written in a general view or a personal view but that's just a preference, it is a good piece to read.