Season names are not capitalized in English unless part of a proper noun or at the beginning of a sentence, as they are considered common nouns.
The names of the seasons are not generally capitalized in English unless they are part of a proper noun or at the beginning of a sentence. This is because seasons are considered common nouns rather than proper nouns, which are specific names of places, people, or things and require capitalization.
For example, 'spring' is not capitalized in 'We will plant trees in the spring,' but 'Spring Semester' is capitalized because it is part of a proper name. Similarly, one should capitalize 'Earth' when referring to it as the planet, but not when using it in a general sense, such as 'down to earth.' The treatment of words like 'Sun' and 'Moon' is similar; they are capitalized when referred to as celestial bodies, but not when used in general terms.