Are particular seasons proper nouns?
Should fall be capitalised in the following? If yes, is it because Fall 2011 is a proper noun?
Where should an app be released in Fall 2011?
Context.
In a Wikipedia article, Avatar (2009 film), a particular summer is capitalised (my emphasis):
Work on the language for the film's extraterrestrial beings began in Summer 2005, and Cameron began developing the screenplay and fictional universe in early 2006.
(The related question Should the names of seasons be capitalized? is about the seasons themselves (as in I love the colors of the leaves in autumn.), not a particular season, like Fall 2011.)
I'm not really interested in OP's should. He can choose which style guide he wants to follow, and take their advice.
Obviously if the season itself is part of a compound name (an event, academic term, publication issue, as per @Gnawme's examples), it's capitalised just like the other words.
As regards what people actually write in other contexts, instances of last summer,summer 1995 in Google Books suggest people usually capitalise the latter, but not the former. I believe this is because even though both terms reference a single specific season, including the actual year makes it more of a "proper noun" with a single referent which never changes.
By contrast, last summer is a more ephemeral concept - last year it was this summer, and by next year it'll need far more words to identify exactly which one we're talking about. In such usages, the name of the season behaves more like a pronoun - we capitalise John, but not the more generic he (unless "He" is [a] God).
Various style manuals and guides (MLA, Chicago, Guardian, Grammar Girl) tend to concur:
- The four seasons are lowercased.
- Except when part of a formal name, such as the name of an event (Winter Olympics), school term (Spring Quarter 2012), or issue of a journal (Summer 2008).
- Except when the season is personified, as in poetry ("Then Spring--with her warm showers--arrived.").
According to Swan's Practical English Guide , capitalization of seasons is not normal:
We use capital letters at the beginning of .... the names of days, months and public holidays( but not usually seasons) e.g. Sunday, Tuesday, but autumn, summer.
"Summer" and "autumn" is only capitalized, when used in poetry, and the season is being personified, for example:
And Winter comes, with the goblet of snow and ice.
But normally, the names of seasons aren't capitalized.
Edit: Due to Peter Mortenson's comment, I'd like to add that:
Seasons are capitalized when used in a title.
The catalog for Spring 2006 will be out in February.
The example given above seems to be of the same type, as the OP's example, namely, when a particular season, of a particular year is given. Thus, I would say, yes, in the OP's example, "Fall" can be capitalized.