Rule 1: Seasons as Generic Nouns
Seasons, such as winter, spring, summer and fall, do not require capitalization because they are generic common nouns. ... This can make some intuitive sense, as you capitalize the days of the week (e.g., Wednesday) and the months of the year (e.g., August).
Does August need a capital letter?
Days, months, and holidays are always capitalized as these are proper nouns. Seasons aren't generally capitalized unless they're personified.
Should you capitalize the name of a season?
The seasons are not proper nouns and are therefore not normally capitalized. Of course, as with other nouns, they should be capitalized at the beginning of sentences and in titles. One poetic exception, is that seasons are sometimes personified, or treated as beings, and in those cases they are often capitalized.
