You should capitalize a season in three specific situations.
Additionally, seasons may be capitalized when they are used in titles or headings. For example: when to capitalize seasons
The short answer:
If the season is part of a title, event name, or trademark, capitalize it. You should capitalize a season in three specific situations
Sometimes writers give human characteristics to a season. In that case, it’s often capitalized as a kind of character. Sometimes writers give human characteristics to a season
Just like any other word in a title, seasons must be capitalized when they appear in the names of books, movies, songs, articles, or academic papers. Standard title capitalization rules apply here (usually capitalizing all words except short prepositions and articles).
While the default is lowercase, there are specific instances where a season transforms from a common noun into a proper noun. In these cases, you must capitalize the first letter.